Question

solve for x.
(8x + 9)°
51°
x =

Explanation:

Step1: Identify angle - relationship

Assume lines $OP$ and $QR$ are parallel. Then, the angle $(8x + 9)^{\circ}$ and the angle adjacent to the $51^{\circ}$ angle (which is $180 - 51=129^{\circ}$) are corresponding angles (if the lines are parallel) and are equal. So, $8x+9 = 129$.

Step2: Solve the equation for x

Subtract 9 from both sides of the equation: $8x=129 - 9$. So, $8x = 120$.

Step3: Isolate x

Divide both sides by 8: $x=\frac{120}{8}=15$.

Answer:

$15$