Question 389107
x+(x+4.5)=20

Remove the parentheses around the expression x+4.5.
x+x+4.5=20

Since x and x are like terms, add x to x to get 2x.
2x+4.5=20

Since 4.5 does not contain the variable to solve for, move it to the right-hand side of the equation by subtracting 4.5 from both sides.
2x=-4.5+20

Add 20 to -4.5 to get 15.5.
2x=15.5

Divide each term in the equation by 2.
(2x)/(2)=(15.5)/(2)

Simplify the left-hand side of the equation by canceling the common factors.
x=(15.5)/(2)

Divide 15.5 by 2 to get 7.75.
x=7.75 feet shorter piece
7.75+4.5=12.25 feet (longer piece)