The correct answer would be a because you have to multiply and get it
Answer:

Step-by-step explanation:
- this can be done by simple manipulation .
- in the given equation, A is the subject.
- so, by the above statement you can understand the meaning of making something as a subject.
- given equation: A = 1/2 bh
- multiply both the sides by 2,
2A = bh
- divide both the sides by h,

so, the required form is : 
First one. PNO =22 MNO =40
4 is the base because the formula for a triangle is base times height divided by two, you would know that 8 times 4 would equal 32. When divided by 2 it would equal 16 which is the area. So 4 is the answer.
7 + 2x - 6 = -3x - 3 - 4
2x + 1 = -3x - 3 - 4
2x + 1 = -3x - 7
2x + 1 + 3x = -7
5x + 1 = -7
5x = -7 - 1
5x = -8
x = -8/5.