15h - 4 = 6
Two step problem

h = 10/15

Step-by-step explanation:

Isolate the variable, h. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.

PEMDAS is the order of operation, and stands for:

Parenthesis

Exponents (& Roots)

Multiplication

Division

Addition

Subtraction

First, add 4 to both sides of the equation:

15h - 4 (+4) = 6 (+4)

15h = 6 + 4

15h = 10

Next, divide 15 from both sides of the equation:

(15h)/15 = (10)/15

h = 10/15 or 0.667 (rounded)

B or #2). It does because 16=10+6, and the model shows 3 groups of 10 and 3 groups of 6.