Question

What are the solutions of the equation (x 2)2 – 2(x 2) – 15 = 0? use u substitution to solve.

Answer 1

The solution of the equation is x=3 or x=-5.

Given that the equation is (x+2)²-2(x-+2)-15=0 and use u substitution method to solve.

Let's assume that the (x+2)=u.

The given equation is rewritten as u²-2u-15=0.

Factorize the quadratic equation by adding or subtracting two number that gives the sum of -2u and product 15u² as

u²-5u+3u-15=0

u(u-5)+3(u-5)=0

Taking out (u-5) as common and get

(u-5)(u+3)=0

Compare each equation with 0 and get

u-5=0 or u+3=0

u=5 or u=-3

Performing back substitution by substituting the values of u in x+2

when u=5 then x is

x+2=5

x=3

And when u=-3 then x is

x+2=-3

x=-5

Hence, the solutions of the (x+2)²-2(x-+2)-15=0 is x=3 and x=-5.

Learn about the substitution here brainly.com/question/12802700

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