to find the area of a rectangle is LxW=A
plug in the given numbers you have
L = 7
W = x-8
A = 42
7 * x-8 = 42
7x-56= 42
solve for X
Edit to reflect comments:
3^-1=1/3
4^-1=1/4
Flip the fraction over basically i.e. 4/1---->1/4
Since all the sides add up to 10x+2, that means that 10x-2-<side1>-<side2>=<side3>. Plugging it in, we have 10x-2-5x-(2x+9)=side3, and 5x-2-(2x+9)=side3, then expanding it to 5x-2-2x-9=3x-11=side3
Answer:
(-1,1) because -1 and 1 are not inclusive
Step-by-step explanation:
from x = -1 to x = 1, the y-value keeps decreasing from 4 to 2
there is another one, (3,5)