Question

Solving Quadratic Equations

Directions: Solve the following quadratic equations using the quadratic formula. Show your work
and all answers must be in simplest radical form.
I
a. x2 - 2x - 15 =0
b. x2 + 8x - 10 =0

Answer 1

a) x= 5 or x= -3

b) x = -4 +
`√(26)` or -4 -
`√(26)`

Explanation:

a)
`x^(2)` - 2x - 15 =0

x =
`\frac{-(-2) +\sqrt{(-2)^(2) - 4(1)(-15)}}{2(1)}` or
`\frac{-(-2) -\sqrt{(-2)^(2) - 4(1)(-15)}}{2(1)}`

x= 5 or x=-3

b)
`x^(2)` + 8x - 10 =0

x =
`\frac{-(8) +\sqrt{(8)^(2) - 4(1)(-10)}}{2(1)}` or
`\frac{-(8) -\sqrt{(8)^(2) - 4(1)(-10)}}{2(1)}`

x = -4 +
`√(26)` or -4 -
`√(26)`