Math
posted by ASDFGHJKL; .
A = h/2 (a+b)
the subject of the given formula is "a" not "A"
please include workings (along with solution) thanks

this topic that i learned in class is "changing the subject of a formula" FYI

Use algebra to derive the formula for a in terms of h, A and b.
You should use parentheses to show if (a+b) is part of the denominator of a fraction h/[2(a+b)], or not. I will assume you mean
A = (h/2)*(a+b)
a + b = 2A/h
a = 2A/h b 
God bless you. Thanks!