Answer:
x= 3.5
Explanation:
Substitute the variable x with what it's equal to, x= 20-y
7(20-y)-8= y
Distribute into the parenthesis.
140-7y-8= y
Subtract common numbers.
(140-8)-7y= y
132-7y= y
Move the constant to the right.
132-7y= y
-132 -132
-7y= y-132
Subtract y to both sides.
-7y= y-132
-y -y
-8y= -132
Divide to both sides by -8
-8y= -132
-8 -8
y= 16.5
Now, add the y value to the equation.
x= 20- (16.5)
x= 3.5