og ps 69

[resilient]

y(3x-5/2)=y

y cannot = 0

x=?



the algebra is simple but solution in book set 3x-5/2=1

this yields the answer choice C..how did you know to set it equal to 0?

a.2/3
b.5/3
c.7/3
d.1
e.4

[Stuart@KaplanGMAT]

y(3x-5/2)=y

y cannot = 0

x=?



the algebra is simple but solution in book set 3x-5/2=1

this yields the answer choice C..how did you know to set it equal to 0?

a.2/3
b.5/3
c.7/3
d.1
e.4

When we're asked to solve for a variable, we want to isolate that variable.

So:

y(3x-5/2)=y

divide both sides by y to get:

(3x-5)/2 = 1

multiply both sides by 2 to get:

3x - 5 = 2

add 5 to both sides to get:

3x = 7

divide both sides by 3 to get:

x = 7/3

[resilient]

can I also argue my way out of this question by explaining that the one of the two parantheses must be equal to 0 and i can just backsolve one of the options that will yield a 0?

[Stuart@KaplanGMAT]

can I also argue my way out of this question by explaining that the one of the two parantheses must be equal to 0 and i can just backsolve one of the options that will yield a 0?

What parenthesis? Why does something have to be equal to 0? There are no 0s in the solution that I provided.