Every x value should have only one value of y.
So the answer is the last choice.
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
20: 1,2,4,5,10,20
28: 1,2,4,7,14,28
3 3/4÷ 1/4
15/4÷1/4
15/4÷4/1
15*4=60
4*1=4
60/4=15
15 times 1/4 can fit into 3 3/4.