Question #d2ca6

1 Answer
Dec 4, 2016

#b= (2A)/9-35 = 2/9 A-35#

Explanation:

The formula for the area of a trapezois is #A=((b_1+b_2)h)/2#,

where #b_1# and #b_2# are the lengths of the bases and #h# is the height.

In this example,

#A=(9(b+35))/2#, find #b#

#2*A=(9(b+35))/cancel2 *cancel2color(white)(aaa)#Multiply both sides by 2

#2A=9(b+35)#

#(2A)/9=(cancel9(b+35))/cancel9color(white)(aaa)#Divide both sides by 9

#(2A)/9color(white)(aa)=b+35#

#color(white)(a)-35color(white)(aaa)-35color(white)(aaa)#Subtract 35 from both sides

#(2A)/9-35=b#

This can also be written as #b= 2/9 A -35#