Question

This is confusing someone help please

Answer 1

Answer:

Below in BOLD.

Step-by-step explanation:

5x^2 - 6x - 2 = 0

Quadratic formula for ax^2 + bx + c = 0  is

x =  [-b ± √(b^2 - 4ac)]/ 2a    

Here we have a = 5, b = -6 and c = -2

so x =  [-(-6)  ± √((-6)^2 - 4*5*-2)]/ 2*5

=  [ 6 ± √(36 + 40)] / 10

= 0.6 ±  √76 / 10

= 0.6 ±  0.8718

= 1.4718,  -0.2718

= 1.5, -0.3 to one decimal place.

x^2 + 3x = 40

x^2 + 3x - 40 = 0

We can factor this one:

(x - 5)(x + 8) = 0

x - 5 = 0 giving x = 5 and

x + 8 = 0 giving x = -8.

Answer  x = -8, 5.