Answer:
x = 
Step-by-step explanation:
We can start simplifying this equation by expanding the parenthesis and cross multiplying.

The exponent 5 and 7x are equal:
Divide both sides by 7

-Chetan K
Area of the first one is has a area of 162
the second one has a area of 189
the third one has an area of 162
the fourth one has a area of 12
C^2+7 would equal 88. the first equation states that C=9, so you can just plug in 9 for C