Answer:
C) Multiply the first equation by 2, and multiply the second equation by 5.
Explanation:
Given equations are :
4x − 5y = 4
and
3x+2y = −20
Now we need to select the best possible first step to solving the system by first eliminating the y variable. Where given choices of the possible steps are:
A) Multiply the first equation by −2, and multiply the second equation by 5.
B) Multiply the first equation by 2, and multiply the second equation by −5.
C) Multiply the first equation by 2, and multiply the second equation by 5.
D) None of the above
Since we need to eliminate y, then we must make coefficients of y equal in both equations. Easiest way is to multiply coefficient of first equation into 2nd equation and multiply coefficient of y from 2nd equation into first equation. Make sure that their sign is oppsite.
Hence correct choice is C)Multiply the first equation by 2, and multiply the second equation by 5.