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(HELP ASAP PLEASE!!)
Two brothers went shopping at a back-to-school sale where all shirts were the same price, and all the shorts too. The younger brother spent $79 on 4 new shirts and 3 pairs of shorts. The older brother purchased 7 new shirts and 8 pairs of shorts and paid a total of $185. How much did each item cost?

Each shirt cost $ ___ and each pair of shorts cost $ ___ .

Respuesta :

AlpenGlow

Answer:

Shirts = $7

Shorts $17

Step-by-step explanation:

Let:

T - shirts

S - shorts

We can make two equations out of this problem:

4T + 3S = $79

7T + 8S = $185

Through substitution we can solve for one of the unknowns. We make one equation to solve for an unknown

[tex]4T+3S=\$79\\\\3S = \$79-4T\\\\S=\dfrac{\$79-4T}{3}[/tex]

We use the formula of S and insert it into the other equation:

[tex]7T+8(\dfrac{\$79-4T}{3}) = \$185\\\\7T + \dfrac{\$632-32T}{3}=\$185\\\\\dfrac{\$632-32T}{3}=\$185-7T\\\\\$632-32T=3(\$185-7T)\\\\$632-32T=\$555 - 21T\\\\-32T+21T=\$555-\$632\\\\-11T=-\$77\\\\\dfrac{-11T}{11}=\dfrac{-\$77}{11}\\\\T = \$7[/tex]

Thus T-shirts are $7 each.

Now that we know T, we can use it to solve for the other unknown. You can use it on any of the formulas.

[tex]4T+3S=\$79\\\\4(\$7) + 3S = \$79\\\\\$28+3S =\$79\\\\3S=\$79-\$28\\\\3S=\$51\\\\S=\dfrac{\$51}{3}\\\\S = \$17[/tex]

We know then that Shorts are $17 each.

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