Answer:
y=-x^2 is just y=x^2 reflected over the x-axis. In other words, the parabola is upside-down.
Step-by-step explanation:
Percentage by which the gas tank of the car is full = 40%
Amount of gas in the gas tank = 8 gallons
Let us assume the capacity of the gas tank = x gallons
Then
40% * x = 8
(40/100) * x = 8
4x/10 = 8
4x = 8 * 10
4x = 80
x = 80/4
= 20 gallons
So the total capacity of the gas tank of the car is 20 gallons. I hope the procedure is clear to you.
Answer: 
Step-by-step explanation:
Given : Two opposite sides of a rectangle are each of length x.
Let the other adjacent side be y.
The perimeter of the rectangle is 12 units.
Perimeter of rectangle is given by :-
The area of rectangle is given by :-
Hence, the area as a function x =
x-2y = -2
x-2(-3x+8)=-2
mutiply the bracket by -2
(-2)(-3x)=6x
(-2)(8)=-16
x+6x-16=-2
7x-16=-2
move -16 to the other side
sign changes from -16 to +16
7x-16+16=-2+16
7x= -2+16
7x= 14
divide both sides by 7
7x/7=14/7
x=2
Find y by using the substitution method
y=-3x+8
y=-3(2)+8
-6+8
=2
Answer:(2,2)
