Question

Hiroko is trying to find the value of d in 10d + 490 = 2,500. he starts by correctly rewriting the equation as 10(d + 49) = 10(250). How could this help Hiroko figure out the value of d?

Answer 1

Hiroko removed common factors, which leads to smaller numbers, which can be easier to work with.

Explanation:

However, this step is not entirely needed in the grand scheme of solving the problem. It simply uses smaller numbers to digest.

Do the opposite of PEMDAS when isolating the variable, d. Note the equal sign, what you do to one side of the equal sign, you do to the other.

PEMDAS is the order of operations, and stands for:

Parenthesis

Exponents (& Roots)
Multiplication

Division

Addition

Subtraction.

First, subtract 490 from both sides of the equation:

10d + 490 (-490) = 2500 (-490)

10d = 2500 - 490

10d = 2010

Next, divide 10 from both sides of the equation:

(10d)/10 = (2010)/10

d = 2010/10

d = 201

201 is your value for d.

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