Question

please solve this fastly​

Answer 1

Answer:

(a) and (c) is quadratic equation

Answer 2

Answer:

Step-by-step explanation:

a.] (4 - x)(3x + 1) = 2- 3x^2

=> 12x + 4 - 3x^2 - x = 2 - 3x^2

=> 11x + 4 = 2 - 3x^2 + 3x^2

=> 11x + 4 = 2

There it is not a quadratic equation but linear

b.] (x + 3)^3 - 5 = x^2 + 9

=> x^3 + (3)^3 + 3(x)^2(3) + 3(x)(3)^2 - 5 = x^2+ 9

=> x^3 + 27 + 9x^2 + 27x - 5 = x^2 + 9

=> x^3 + 8x^2 + 27x + 13 = 0

therefore it is not a quadratic but cubic

c.] (k - 4)x^2 + 3x = 9 {Given: k =4}

=> (4 - 4)x^2 + 3x = 9

=> 3x = 9

therfore not a quadratic but linear

d.] (x+1)^3 = x^3 - 5

=> x^3 + 1 + 3x^2 + 3x = x^3 - 5

=> 3x^2 + 3x + 1 = - 5

=> x^2 + 3x + 6 = 0

Therfore it is a quadratic

(So I took it as find the value of x instead of finding which of them were quadratic)