Question

Which of the following is not a quadratic equation:

(a) (x−2)2+ 1 = (2x – 3)
(b) (x+2)3= x3 – 4

(c) x(2x + 3) = x2 + 1
(d) x(x + 1) + 8 = (x + 2) (x – 2)2​

Answer 1

ANSWER
i)
(x+1)
2
=2(x−3)
x
2
+2x+1=2x−6
x
2
+7=0 → Quadratic

ii)
x
2
−2x=−2(3−x)
x
2
−2x=−6+2x
x
2
+4x+6=0 → Quadratic

iii)
(x−2)(x+1)=(x−1)(x+3)
x
2
−x−2=x
2
+2x−3
3x=1 → Non Quadratic

iv)
(x−3)(2x+1)=(x)(x+5)
2x
2
−5x−3=x
2
+5x
x
2
+10x−3=0 → Quadratic

v)
(x−3)(2x−1)=(x−1)(x+5)
2x
2
−7x+3=x
2
+4x−5
x
2
−11x+8=0 → Quadratic

vi)
x
2
+3x+1=(x−2)
2

x
2
+3x+1=x
2
−4x+4
7x=3 → Non Quadratic

vii)
(x+2)
3
=2x(x
2
−1)
x
3
+8+6x(x+2)=2x
3
−2x
x
3
+8+6x
2
+12x=2x
3
−2x
−x
3
+6x
2
+14x+8=0 → Non Quadratic

viii)
x
3
−4x
2
−x+1
=x
3
+3x
2
(−2)+3x(−2)
2
+(−2)
3

x
3
−4x
2
−x+1=x
3
−6x
2
+12x−8
x
3
−4x
2
−x+1−x
3
+6x
2
−12x+8=0
2x
2
−13x+9=0 → Non Quadratic

Answer 2

Answer:

Pls check if it is correct or not