21=.5h(2+1)

Solution for 21=.5h(2+1) equation:

Simplifying
21 = 0.5h(2 + 1)

Combine like terms: 2 + 1 = 3
21 = 0.5h(3)

Reorder the terms for easier multiplication:
21 = 0.5 * 3h

Multiply 0.5 * 3
21 = 1.5h

Solving
21 = 1.5h

Solving for variable 'h'.

Move all terms containing h to the left, all other terms to the right.

Add '-1.5h' to each side of the equation.
21 + -1.5h = 1.5h + -1.5h

Combine like terms: 1.5h + -1.5h = 0.0
21 + -1.5h = 0.0

Add '-21' to each side of the equation.
21 + -21 + -1.5h = 0.0 + -21

Combine like terms: 21 + -21 = 0
0 + -1.5h = 0.0 + -21
-1.5h = 0.0 + -21

Combine like terms: 0.0 + -21 = -21
-1.5h = -21

Divide each side by '-1.5'.
h = 14

Simplifying
h = 14