I am assuming you wrote the problem wrong. Is it a^2?
A^2 -4A-21=0
(A-7)(A+3)=0
A=7 A=-3, ignore the negative number because it doesn't make sense if you plug in for a.
length=a+3=7+3=10
Width=7=a
Answer:
trueeee :) that is my answer
Answer:
y = 1/40x + 20
Step-by-step explanation:
Slope-intercept equation format:
y = mx + b
m = slope/ gradient/ constant of variation/ rate of change
b = y-intercept
To find the slope, use the formula:

Find two random points:
1 - (0.5, 40) , 2 - (1, 60)
Plug in:

Solve:

Divide:

The y-intercept is when the x-coordinate is equal to 0.
The y-intercept is always the beginning.
So observing the graph, the first point is (0, 20)
The x-coordinate is 0.
Y intercept = 20.
Plug in both slope and y-intercept:
y = 1/40x + 20