Answer:
r = -6
Step-by-step explanation:
6r + 7 = 13 + 7r
-6r both sides
7 = 13 + r
-7 both sides
r + 6 = 0
-6 both sides
r = -6
First you have to have the absolute value isolated so the 2 has to be divided. Then set up the two cases and solve.
You can use Substitution to solve this problem:
4x-y=20
-y=-4x+20
y=4x-20
Now you have two equations, and you use the first one to substitute into the second one.
y=4x-20 and -2x-2y=10
-2x-2(4x-20)=10
-2x-8x+40=10
-10x+40=10
-10x=-30
-x=-3
x=3
Now that we have figured out what x is, we can substitute x in to one of the equations to figure out y.
4x-y=20 x=3
4(3)-y=20
12-y=20
-y=8
y=-8
<em><u>So your answer would be x=3 and y=-8</u></em>