Answer:
Step-by-step explanation:
substitute the value of y in the first equation.
7x-3(5x-4)=20
7x-15x+12=20
-8x=20-12
x=8/-8
x= -1
then you substitute the value of x on the y equation to find y
y=5×-1 -4
y= -5-4
y= -9
Answer:

Step-by-step explanation:
The explanation is pinned.
plz give me Brainliest and 100 points.
Answer:mean
Step-by-step explanation:
I would assume it’s the mean since that averages the 7 test scores it represents the data set well. Outlier and mode don’t describe a data set since they are quite unique within it.
Answer:
A = x^2 + 4x -21
Step-by-step explanation:
L = x+7
W = x-3
A = L*W
A = (x+7)(x-3)
A = x^2 + 4x - 21