Question

Which of the following are quadratic equations? (i) 16x2−3=(2x+5)(5x−3) (ii) (x+2)3=x3−4 (iii) x(x+1)+8=(x+2)(x−2)

Answer 1

3

Explanation:

because it consists two side separated by equal sign and has letters in it

Answer 2

Explanation:

Rearranging:

(i) 16x2−3=(2x+5)(5x−3)

16x^2 - 3 = 10x^2 + 19x -15

6x^2 - 19x + 12 = 9

THIS IS QUADRATIC.

(ii) (x+2)3=x3−4

(x + 2)(x + 2)^2 = x^3 - 4

(x + 2)(x^2 + 4x + 4) = x^3 - 4

x^3 + 4x^2 + 4x + 2x^2 + 8x + 8 = x^3 - 4

6x^2 + 12x + 4 = 0.

THIS IS QUADRATIC.

(iii) x(x+1)+8=(x+2)(x−2)

x^2 + x + 8 = x^2 - 4

x + 12 = 0

THIS IS NOT QUADRATIC.