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Elsa H
Elsa H

Malaysia

Please explain, i don't understand the rounded part!! :' (

Date Posted: 6 years ago
Views: 382
snell
Snell
6 years ago
note:
(x+2)² is equal to x² + 4x + 4,
not x² + 4

(x+2)² = 2x + 7
=> x² + 4x + 4 = 2x + 7
=> x² + 2x - 3 = 0
=> (x+3)(x-1) = 0
=> (x+3) = 0 or (x-1) = 0
=> x = -3 or x =1

so, ur steps are incorrect,
but ur ans happens to b correct, by chance.

bcos ur step:
x² - 2x - 3 = 0
shld b (x-3)(x+1) = 0,
not (x+3)(x-1) = 0
Elsa H
Elsa H
6 years ago
Oh my fault
Elsa H
Elsa H
6 years ago
Now i'm understand
Elsa H
Elsa H
6 years ago
Tq!!

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Goh Zhi Yan
Goh Zhi Yan's answer
3 answers (Tutor Details)
1st
Hello!
I think you have expanded (x+2)^2 wrongly, hence you got x^2 - 2x -3 = 0 instead of x^2 + 2x - 3 = 0.

I have also shown how you can simplify x^2 + 2x - 3 to (x-1)(x+3) in the grey box.