Question

ERROR ANALYSIS Describe and correct the error in solving the equation.

❌ 2(x+1)²+3=21
2(x+1)²=18
(x+1)²=9
x+1=3
x=2

Answer 1

I don’t know I just need more points tbh

Answer 2

see explanation

Explanation:

the error is in the line x + 1 = 3 , that is

2(x + 1)² + 3 = 21 ( subtract 3 from both sides )

2(x + 1)² = 18 ( divide both sides by 2 )

(x + 1)² = 9 ( take square root of both sides )

x + 1 = ±
`√(9)` = ± 3 ← note ±

subtract 1 from both sides

x = - 1 ± 3

Then

x = - 1 - 3 = - 4 , or

x = - 1 + 3 = 2

That is a quadratic equation has 2 solutions