Question

Solve the following: a. 4x^2 + 5x + 3 = 2x^2 − 3x b. c^2 − 14 = 5c

Answer 1

Answer:

(a) x = -0.418 , -3.581

(B) c = 6.855, -1.855

Step-by-step explanation:

(A) We have given equation $4x^2+5x+3=2x^2-3x$

$2x^2+8x+3=0$

On comparing with standard quadratic equation $ax^2+bx+c$

a = 2, b = 8 and c = 3

So roots of the equation will be $x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}=\frac{-8\pm \sqrt{8^2-4\times 2\times 3}}{2\times 2}=\frac{-8\pm 6.324}{4}=-0.418,-3.581$

(b) $c^2-14=5c$

$c^2-5c-14=0$

a = 1, b = -5 and c= -14

So $c=\frac{-b\pm \sqrt{b^2-4ac}}{2a}=\frac{-(-5)\pm \sqrt{(-5)^2-4\times 1\times (-14)}}{2\times 1}=\frac{5\pm 8.71}{2}=6.855,-1.855$