Question

Which of these shows the result of using the first equation to substitute for y in the second equation, then combining like terms?

y = 3x
2x + 3y = 55

A. 11x = 55
B. 5x = 55
C. 9x = 55
D. 5y = 55

Answer 1

i'm thinking C,  9x=55

Answer 2

Answer: A(11x=55)

Explanation:

in the equation 2x + 3y = 55, subsitute 3y for 3x, because y = 3x. this will result in the equation 2x + 3(3x) which equals 11x. so 11x=55