Question

What should be the first step in adding these equations to eliminate y?

3x + 4y = 8
+ 6x – 2y = 9

A. Multiply the top equation by 6.
B. Multiply the top equation by 2.
C. Multiply the bottom equation by 2.
D. Multiply the bottom equation by 3

Answer 1

C. Multiply the bottom equation by 2

Answer 2

Answer:

(C) Multiply the bottom equation by 2.

Step-by-step explanation:

The given equation are:

$3x+4y=8$                                (1)

and $6x-2y=9$                         (2)

Now, in order to add these equations and eliminate y, we should multiply the bottom equation by 2, thus we have

$3x+4y=8$                                (3)

$12x-4y=18$                              (4)

Now, adding the above equations, we have

$15x=26$

$x=\frac{26}{15}$

Now, substituting the value of x in equation (3), we have

$3(\frac{26}{15})+4y=8$

$y=\frac{7}{10}$

Therefore, option (C) is correct.