To solve this system of equations by elimination, what operation could be used to eliminate the x-variable and find the value of y?

4x + 3y = 6

18x + 5y = 6

a) subtract 2 times the second equation from 9 times the first equation

b) subtract 9 times the second equation from 2 times the first equation

c) subtract 3 times the second equation from 5 times the first equation

d) subtract 5 times the second equation from 3 times the first equation

ANSWER

A)subtract 2 times the second equation from 9 times the first equation

EXPLANATION

First equation: 4x+3y=6

Second equation: 18x+5y=6.

We want to solve this equation by first eliminating the x-variable.

So we multiply the second equation by by 2 to get;

Third equation: 36x+10y=12.

We now multiply the first equation by 9.

Fourth equation: 36x+27y=54

If we subtract the third equation from the fourth equation we get:

27y-10y=54-12

17y=42

y=42/17

We have now eliminated the variable x, and we can solve for y.

The correct answer is A.