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Unit 4 homework 9 gina wilson all things algebra 2015

Unit 4 homework 9 gina wilson all things algebra 2015-example-1
User Bhavna
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The perimeter of the triangle is 30 units.

How to form equation from word problem.

From the description

The triangle is a right-angled triangle

let hypotenuse = x

longer side = x - 1

shorter leg = x-8

Using Pythagorean theorem

hyp² = longer leg² + shorter leg²

x² = (x-1)² + (x-8)²

Expand

x² = (x-1)(x-1)+(x-8)(x-8)

x² = (x²-x-x + 1)+(x²-8x-8x +64)

x² = (x² -2x + 1) + (x² - 16x + 64)

Collect like terms

x² - x² -x² +2x +16x -1 -64 = 0

-x² + 18x -65 =0

x² -18x +65 = 0

let's solve the quadratic equation

x² - 18x + 65 = 0 .

We can factor it as (x-13)(x-5) = 0.

So, the solutions are x = 13 and x = 5.

x cannot be 5 because x -8: 5-8 = -3

hypotenuse , x = 13

Longer leg, x-1 = 13 -1 = 12

Shorter leg, x-8 = 13-8 = 5

Perimeter = hypotenuse+longer leg + shorter leg

P = 13 + 12 + 5

= 30 units

Unit 4 homework 9 gina wilson all things algebra 2015-example-1
User Oscar Del Ben
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7.9k points