Solve using the quadratic formula: x2 – 10x – 1 = -10?

Answer 1

x^2 - 10x + 9

U can factor it, but if u want to use the quadratic formula it is,

x = [-b +/- (b^2 - 4ac)^1/2]/2a

x = {-(-10) +/- [100 - 4(1)(9)]^1/2 }/2

x = [10 +/- 8 ]/2

x = (10 - 8)/2 = 1
or
x = (10 + 8)/2 = 9

x = 1, x = 9

Answer 2

Quadratic formula is (-b + sq.root(b^2 - 4ac))/2a OR (-b - sq.root(b^2 - 4ac))/2a

so, you set the equation equal to zero.

x^2 - 10x -1 = -10 becomes
x^2 - 10x +9 = 0

substitute the numbers in the equation into the formula using the method

ax^2 + bx + c = 0


you can use factoring to make it even easier.

x^2 - 10x +9

(x-9)(x-1)
they give you exact answers

Answer 3

Rearrange to get x^2 -10x + 9 = 0. The left side is easily factored to get (x-1)(x-9), so the roots are 1 and 9.

Answer 4

x² - 10x + 9 = 0
x = [ 10 ± √(100 - 36) ] / 2
x = [10 ± √64] / 2
x = [10 ± 8] / 2
x = 18 / 2 , x = 2 / 2
x = 9 , x = 1
Check
x² - 10 + 9 = 0
(x - 9) (x - 1) = 0
x = 9 , x = 1

Answer 5

you need to set it equal to zero first, you do this dy adding 10 to both sides, you get: x^2-10+9=0
to factor this, the easiest way would be to ask what are factors of 9 whose sum is -10, those factors are -1, -9
so this factors into (x-1)(x-9)=0 setting each one of the factors equal to zero gives x=1 and x=9