Question

Suppose that 3y - 5 = 45 and y = 3x - 2.Which of the following equations is equivalent to 3y - 5 = 45, but written only in terms of x?

Answer 1

We have

$\begin{gathered} 3y-5=45 \\ y=3x-2 \end{gathered}$

So we must replace the value of y of the second equation in the first equation

$\begin{gathered} 3(3x-2)-5=45 \\ 9x-6-5=45 \\ 9x-6=45+5 \\ 9x-6=50 \end{gathered}$

So, the answer is 9x - 6 = 50. Last option.