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πŸ“ Division Property of Equality (13 MCQs)

πŸ“– From Digital SAT Algebra β€’ 2. Linear Equations And Inequalities β€’ 13 questions available

What is Division Property of Equality?

Definition:
The Division Property of Equality states that if you divide both sides of an equation by the same nonzero number, the equality is maintained. Formally, if a=ba = b and c≠0c \neq 0, then a/c=b/ca/c = b/c. It is specifically used to eliminate multiplication by a constant.

Working:
When you have an equation like 4x=204x = 20, divide both sides by 4 to isolate xx: 4x/4=20/44x/4 = 20/4, resulting in x=5x = 5. The division cancels out the coefficient 4.

Example:
Solve 9z=639z = 63 using Division Property. Divide both sides by 9: 9z/9=63/99z/9 = 63/9, so z=7z = 7. Check: 9(7)=639(7) = 63.

Reason:
This property is the inverse of multiplication, allowing us to undo multiplication and solve for the variable when it has a coefficient.

7
Easy
5
Medium
1
Hard

πŸ“ All Division Property of Equality MCQs

Q1. If βˆ’7x=42-7x = 42, what is the value of xx based on the division property of equality?

A.x=βˆ’6x = -6 βœ…
B.x=6x = 6
C.x=βˆ’7x = -7
D.x=294x = 294
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: The division property states that if you divide both sides of an equation by the same nonzero number, the equality remains true. Here, dividing both sides by βˆ’7-7 gives x=βˆ’6x = -6. It is a direct application.

Q2. Which equation correctly represents the statement: 'A number multiplied by 4 gives 28. Find the number.'?

A.4x=284x = 28 βœ…
B.x/4=28x/4 = 28
C.4+x=284 + x = 28
D.4βˆ’x=284 - x = 28
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: Translating a verbal statement to an algebraic equation requires understanding that 'multiplied by' indicates multiplication. 4x=284x = 28 is the correct model, and solving by division gives x=7x = 7. The other options change the operation.

Q3. A taxi charges a fixed fare of \<span class="katex-error" title="ParseError: KaTeX parse error: Can&#x27;t use function &#x27;' in math mode at position 3: 5 \Μ²)Μ² plus \" style="color:#cc0000">5 plus \</span>2\</span>2 per mile. If the total fare is $25\$25, which equation and solution correctly model the situation?

A.2m+5=252m + 5 = 25; m=10m = 10 βœ…
B.2m=252m = 25; m=12.5m = 12.5
C.5m+2=255m + 2 = 25; m=4.6m = 4.6
D.2m+5=252m + 5 = 25; m=15m = 15
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: The fixed cost is added to the variable cost. So 2m+5=252m + 5 = 25. Subtracting 5 gives 2m=202m = 20, then dividing by 2 gives m=10m = 10. This applies the division property after a subtraction step.

Q4. A student solved 3x=153x = 15 as x=5x = 5. Another solved βˆ’3x=15-3x = 15 as x=βˆ’5x = -5. Which statement about their solutions is true?

A.Both are correct because they correctly divided by the coefficient. βœ…
B.First is correct, second is incorrect because dividing by a negative changes sign.
C.Both are incorrect because division property doesn’t apply to negative numbers.
D.First is incorrect, second is correct because positive divided by positive.
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: The division property applies regardless of sign. For 3x=153x = 15, dividing by 3 gives 5. For βˆ’3x=15-3x = 15, dividing by βˆ’3-3 gives βˆ’5-5. Both students correctly applied the property, showing understanding that sign matters in the result.

Q5. If the graph of y=5xy = 5x passes through the point where y=20y = 20, what is the x-coordinate? Interpret using division property.

A.x=4x = 4 βœ…
B.x=100x = 100
C.x=15x = 15
D.x=0.25x = 0.25
πŸ’‘ Difficulty: hard | βœ… Correct: A

πŸ“– Explanation: On the graph, y=20y = 20 means 5x=205x = 20. Dividing both sides by 5 gives x=4x = 4. This represents the input value that produces the output 20 on the line, linking graphical representation with algebraic solution.

Q6. Compare the two solution methods for 8x=648x = 64: Method A divides by 8, Method B multiplies by 18\frac{1}{8}. Which is correct?

A.Both are correct and equivalent βœ…
B.Only Method A is correct
C.Only Method B is correct
D.Neither is correct
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: Dividing by 8 and multiplying by its reciprocal 18\frac{1}{8} are equivalent operations. Both yield x=8x = 8. This question tests the conceptual understanding that division is multiplication by the reciprocal.

Q7. What is the solution of xβˆ’4=12\frac{x}{-4} = 12? Note: Division property is used differently here.

A.x=βˆ’48x = -48 βœ…
B.x=βˆ’3x = -3
C.x=48x = 48
D.x=3x = 3
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: Here xx is divided by βˆ’4-4. To isolate xx, multiply both sides by βˆ’4-4 (which is the inverse operation, since division property can be extended). x=βˆ’48x = -48. This tests if students recognize that division property can be applied inversely.

Q8. A physics student knows that Force = mass Γ— acceleration, or F=maF = ma. If F=120F = 120 N and a=15a = 15 m/sΒ², what is the mass?

A.m=8m = 8 kg βœ…
B.m=1800m = 1800 kg
C.m=105m = 105 kg
D.m=135m = 135 kg
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: Using F=maF = ma, substitute values: 120=15m120 = 15m. Dividing both sides by 15 gives m=8m = 8. This models real-world application of division property in a scientific formula.

Q9. A student writes 0x=50x = 5 and claims division property gives x=5x = 5. What is the error?

A.Division by zero is undefined, so no solution βœ…
B.Division by zero gives zero, so x=0x = 0
C.Zero divided by zero is 1, so x=1x = 1
D.It is correct because any number divided by 0 is 0
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: The division property requires dividing by a nonzero number. Since the coefficient is 0, dividing both sides by 0 is undefined. The equation 0x=50x = 5 has no solution. This identifies the critical misconception about division by zero.

Q10. Given the equation 4x+8=244x + 8 = 24, a student subtracts 8 first to get 4x=164x = 16, then divides by 4 to get x=4x = 4. What property is used in each step?

A.Subtraction property, then division property βœ…
B.Division property, then subtraction property
C.Only division property used twice
D.Only subtraction property used
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: This question requires identifying two different properties. Subtracting 8 uses the subtraction property of equality; dividing by 4 uses the division property. It tests the sequence and conceptual understanding of multiple properties.

Q11. If βˆ’2x=βˆ’18-2x = -18, which of the following is the result of dividing both sides by -2?

A.x=9x = 9 βœ…
B.x=βˆ’9x = -9
C.x=36x = 36
D.x=βˆ’36x = -36
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: Dividing both sides by βˆ’2-2 gives x=βˆ’18βˆ’2=9x = \frac{-18}{-2} = 9. The signs cancel, producing a positive result. This is a straightforward application of the division property.

Q12. Which of the following is NOT a valid use of the division property of equality?

A.Dividing both sides by 2 in 2x=102x = 10
B.Dividing both sides by -3 in βˆ’3x=12-3x = 12
C.Dividing both sides by 0 in 0x=00x = 0 βœ…
D.Dividing both sides by 0.5 in 0.5x=70.5x = 7
πŸ’‘ Difficulty: easy | βœ… Correct: C

πŸ“– Explanation: Dividing by zero is invalid in any equation, including 0x=00x = 0, because division by zero is undefined. Although the equation is true for all xx, you cannot divide by 0 to solve it. This is a common error.

Q13. If x3=7\frac{x}{3} = 7, solve for xx using the division property after multiplying both sides by 3. What is the result?

A.x=21x = 21 βœ…
B.x=73x = \frac{7}{3}
C.x=3x = 3
D.x=10x = 10
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: Although the equation involves division, we multiply both sides by 3 to isolate xx. This is the inverse operation. The division property is used implicitly because multiplication and division are inverse operations. x=21x = 21.

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