To solve the exercirses which are shown in the figure attached, you must follow the proccedure below:
7) (x)=x³-6x²+8x
(x)=x(x³-6x²+8)
(x)=(x-4)(x-2)x
The lenght is: x
The height is= (x-4)
8) √(2x+8)-6=4
1. You need to clear the variable "x". Then:
√(2x+8)=4+6
√(2x+8)=10
(√2x+8)²=10²
2x+8=100
2x=100-8
x=92/2
x=46
9) l4x+3l=9+2x
1. To solve the left member, you must evaluate two cases: it could be positive,or negative. Then:
2. Negative:
l4x+3l=9+2x
-4x-3=9+2x
-4x-2x=9+3
-6x=12
x=12/-6
x=-2
3. Positive:
l4x+3l=9+2x
4x+3=9+2x
4x-2x=9-3
2x=6
x=6/2
x=3
The answer is C.
This is because 7 must be greater than 12-g.
G cannot equal 5 and below because 12-5=7.
Therefore C is the only answer that works.
The answer would be 53. This can be found by add 127 twice (xy and uz) and subtracting it from 360. This would give you 106 and you would divide it by 2 for the 2 angles left and get the answer.

So, your answer to this problem is
c = 4.