Question

90 POINTS!!

Haley has $155 in savings, and her brother Hank has $230. Hayley is saving $10 each week and her brother is spending $15 each week. After how many weeks will their savings account have the same amount of money in them?

Answer 1

3 weeks

Explanation:

Set the equations. Let "amount of weeks" be signified by the variable, x.

First, note that Haley starts with $155, and saves $10 each week:

10x + 155

Next, note that her brother has $230 saved and spends $15 each week:

230 - 15x.

Set the two equations equal to each other:

10x + 155 = 230 - 15x

Isolate the variable, x. 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 operations, and stands for:

Parenthesis

Exponents (& Roots)

Multiplications

Divisions

Additions

Subtractions

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First, subtract 155 and add 15x to both sides of the equation:

10x (+15x) + 155 (-155) = 230 (-155) - 15x (+15x)

10x + 15x = 230 - 155

25x = 75

Next, divide 25 from both sides of the equation:

(25x)/25 = (75)/25

x = 75/25 = 3

3 weeks is your answer.

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