Question

Need help on #7 please !!!

Answer 1

x = 8

Explanation:

Since the triangle is right use Pythagoras' theorem

The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is

(x + 9)² = x² + 15² ← expand factor on left side

x² + 18x + 81 = x² + 225 ( subtract x² from both sides )

18x + 81 = 225 ( subtract 81 from both sides )

18x = 144 ( divide both sides by 18 )

x = 8

Answer 2

Solve by using Pythagoras triangle concept

x^2 + 15^2 = (9+x)^2

x^2 + 225 = 81 + 18x + x^2

x^2 - x^2 + 225 - 81 = 18x

144 = 18x

144/18 = x

x = 8