A=1/2h(a+b) for a
not sure what to do here

a = (2A)/h - b

Step-by-step explanation:

A=1/2h(a+b) for a

Multiply both sides by 2:

2A=h(a+b)

Divide both sides by h:

(2A)/h = a + b

Subtract b from both sides:

(2A)/h - b = a

Switch sides:

a = (2A)/h - b

your answer is 23/2 - 13.5

step-by-step explanation:

7/2 evaluates to

multiply x and 4.5

multiply x and 1

the x just gets copied along.

the answer is x

x

4.5*x evaluates to 4.5x

multiply 3 and 4.5x

multiply 1 and x

the x just gets copied along.

x

4.5*x*3 evaluates to 13.5x

7/2-4.5*x*3 evaluates to

  + 8 =

the answer is

7/2-4.5*x*3+8 evaluates to