What is the value of b2 - 4ac for the following equation?

2x^2 - 2x - 1 = 0​

Step-by-step explanation:

Standard quadratic equation :

Given equation :

From the given equation , a = 2, b = -2 , c = -1

Therefore,

answer: i wpould go with c

step-by-step explanation:

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.