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Unit 6 homework 2 need help

Unit 6 homework 2 need help-example-1
User YuriW
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1 Answer

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∆PQR and ∆SQT are similar, so corresponding sides occur in fixed ratios with one another. This means

SQ / PQ = ST / PR

Solve for x :

8 / ((x + 5) + 8) = (x - 9) / 21

8 / (x + 13) = (x - 9) / 21

168 = (x - 9) (x + 13)

168 = x² + 4x - 117

x² + 4x - 285 = 0

(x + 19) (x - 15) = 0

⇒ x = -19 or x = 15

But x can't be smaller than 9, otherwise ST = x - 9 would be a negative length. So x = 15.

User MattDiMu
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