What are the solutions of the equation (x + 2) 2 - 2 (x + 2) - 15 = 0? Use u substitution to solve.

Question

Mathematics

Nikolas

28 January, 07:40

What are the solutions of the equation (x + 2) 2 - 2 (x + 2) - 15 = 0? Use u substitution to solve.

+5

Answers (1)

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Jan · Answer 1

Step-by-step explanation:

hello:

(x + 2) 2 - 2 (x + 2) - 15 = 0

let : t = x+2

t²-2t-15 = 0

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

t-5=0 or t+3=0

t=5 or t=-3

but : t = x+2

if : t=5 x+2 = 5 so : x=3

if : t = - 3 x+2 = - 3 so : x = - 5

conclusion two solutions : 3, - 5