So are teacher ‍ gave us the answer but she wants us to to the work and i have tried so hard and i can’t find it

In order to find the shaded region the first thing you have to do is find the area of the two small triangles, then find the area of the big triangle. Subtract the area of the small triangles from the big one and that is the area.

Step one: 11×12=132

Step two: 132÷2= 66

Step three: 66+66=132 (because there is two small triangles with same dimensions)

Step four: 40×15=300

Step five: 300-132=168

Answer 168m^2

really really sorry if i'm

-12 -5(x + 4) = 3x

-12 - 5x - 20 = 3x

-12 - 20 - 5x = 3x

-32 - 5x = 3x

    + 5x   + 5x

-32 = 8x

8         8

- 4= x