Question

1/4x + 1/3y = 5 1/2x + 3/2y = 11 Which of the following expressions represents the Multiplicative Property of Equality? 3x + 4y = 60; x + 3y = 22 3x + 8y = 60 ; x + 3y = 22 x + 2y = 60 ; x + 3y = 22 4x + 3y = 60 ; 2x + 2y = 22

Answer 1

Multiplicative property of equality states that if a and b are 2 equal expressions, or numbers, then if we multiply both by a non zero expression c, then the results are again equal.

So if a=b, then ac=bc.


The first equality is 

(i) $\frac{1}{4}x+ \frac{1}{3}y=5$

multiplying both sides by 12, we have:

$12* \frac{1}{4}x+ 12*\frac{1}{3}y=12*5$

3x+4y=60


The second equality is 

$\frac{1}{2}x+ \frac{3}{2}y=11$

multiplying by 2 we get

x+3y=22


Answer: 3x+4y=60; x+3y=22 (the first one only)