The formula for the area of a trapezoid is a=1/2(b¹ + b²)h. When this equation is solved for b¹, one is b¹=2a/h-b². Which of the following is an equivalent equation to find b¹?
a) ( b¹ = 2a/h - b² )
b) ( b¹ = 2ah - b²/h )
c) ( b¹ = a - b²/h )
d) ( b¹ = a/h - b²/2 )