Answer:
A = 400 cm^2
Step-by-step explanation:
The perimeter of a square is given by
P = 4s where s is the side length
80 = 4s
Divide each side by 4
80/4 = 4s/4
20 =s
We want to find the area of the square
A = s^2
A = 20^2
A = 400 cm^2
<span>-1<0
so use 2x+1
2(-1)+1=-2+1=-1
-
</span><span>F(-1) means "Evaluate F(x) when x=-1"
Since -1 is less than 0, this means that F(x) = 2x+1. This is because F(x) = 2x+1 when x < 0</span>
Answer:
a = 9
Step-by-step explanation:
you can simplify the proportion to:
use cross- multiplication
8a = 72
a = 9
Answer:
I got 18.26
Step-by-step explanation:
Added them up
Erica used 50 pounds of type B coffee
Let the number of pounds of type A coffee be A
Let the number of pounds of type B coffee be B
Total number of pounds = 123
A + B = 123.........................................(1)
Cost of 1 pound of type A coffee = $5.95
Cost of 1 pound of type B coffee = $4.40
Total cost = $654.35
5.95A + 4.40B = 654.35..........................(2)
Make A the subject of the formula in equation (1)
A = 123 - B........................(3)
Substitute equation (3) into equation (2)
5.95(123 - B) + 4.40B = 654.35
731.85 - 5.95B + 4.40B = 654.35
5.95B - 4.40B = 731.85 - 654.35
1.55B = 77.5
B = 77.5/1.55
B = 50
Erica used 50 pounds of type B coffee
Learn more on system of equations here here: brainly.com/question/13729904
