Question

Please help for solve this question

Answer 1

You set up the problem correctly, just keep going.

Expand out your expression:

2x(3x-9) + 4x(x+13)
= 6x^2 -18x + 4x^2 + 52x 
= 10x^2 +34x

Remember that the above expression is the area, so it is equal to 24.

10x^2 + 34x = 24
10x^2 + 34x - 24 = 0     (divide by 2)
5x^2 + 17x - 12 = 0

Done.