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

11x=55 just took the test

Answer 2

Answer: A.
`11x=55`

Explanation:

The given system of equations:

`y = 3x.....................(1)\\\2x + 3y = 55.................(2)`

When we substitute the value of y in equation (2), we get

`2x+3(3x)=55\\\\\Rightarrow\ 2x+9x=55\\\\\Rightarrow\ 11x=55`

Hence, the result of using the first equation to substitute for y in the second equation, then combining like terms is
`11x=55`