Question

X2-2X-3=0


-3X2+10X-3=0


X2+X-12=0

Answer 1

1.

∆ = -2² - 4 1 -3

∆ = 4 + 12

∆ = 16

- (-2) ± √16 / 2.1

2 ± 4 / 2

x' = 6/2 = 3

x" = -2/2 = -1

2.

∆ = 10² - 4 -3 -3

∆ = 100 - 36

∆ = 64

- (10) ± √64 / 2.-3

-10 ± 8 / -6

x' = 2/-6 = 1/-3

x" = -18/6 = -3

3.

∆ = 1² - 4 1 -12

∆ = 1 + 48

∆ = 49

- (1) ± √49 / 2.1

-1 ± 7 / 2

x' = 6/2 = 3

x" = -8/2 = -4