Question

a=75(125+81/2) how do you this equation? pls Help!!!

Answer 1

Closing parenthesis is misplaced. Should be: 
A = h(b₁ + b₂)/2 

h = 75 ft 
b₁ = 125 ft 
b₂ = 81 ft 

Then it's just plug & grind: 

A = 75(125 + 81)/2 ft² = 75·206/2 ft² = 75·103 ft² = (7500 + 225) ft² = 7725 ft² 

If you follow that, it will guide you through any other, similar p

Answer 2

 A = 75(125 + 81/2)
A = 75(125 + 40.5)
A = 75(165.5)
A = 12412.5