Answer
$x=2$
Work Step by Step
$y_{1}=9(3x - 5)$ equation 1
$y_{2}=3x - 1$ equation 2
$y_{1}$ is 51 less than 12 times $y_{2}$ --> $y_{1}=12y_{2} - 51$ equation 3
Substitute equations 1 & 2 to equation 3, $y_{1}=12y_{2} - 51$:
$9(3x - 5)=12(3x - 1)-51$
Expand $9(3x - 5)$ = $27x-45$
Expand $12(3x - 1)$ = $36x-12$
Rewrite the equation:
$27x-45 = 36x-12 - 51$
$27x-45 = 36x-63$
Add 45 to both sides:
$27x-45+45 = 36x-63+45$
$27x = 36x - 18$
Simplify:
$-9x = -18$
Divide both sides by -9:
$x=2$