How to solve the quadratic equation?

Question

x(squared) + x - 42 = 0

Answer 1

Using the quadratic equation: (-b^2 +- sqrt (b^2-4ac))/2a

(-1 +- sqrt(1^2-4*1*-42))/2

(-1 +- sqrt(169))/2

(-1 + 13)/2 and (-1 - 13)/2

Answers: 6 and -7

Verify 6

6^2+6-42=0

36+6-42

42-42=0 check

Verify -7

-7^2-7-42=0

49-7-42=0

42-42=0 check

Answer 2

METHOD 1:

x^2 + x - 42 = 0 Factor

(x + 7)(x - 6) = 0 Zero Product Property

x + 7 = 0 Subtract 7 from both sides

x = -7 POSSIBLE ANSWER

x - 6 = 0 Add 6 from both sides

x = 6 POSSIBLE ANSWER

Substitute the answers back into the quadratic and CHECK for any EXTRANEOUS solutions.

METHOD 2:

x = (-b ± √b^2 - 4ac) / 2a Quadratic Formula

Substitute in the numbers for the variables and simplify.

ax^2 + bx + c

In this case, a = 1, b = 1, c = -42

Answer 3

x^2+7x-6x-42=0

x(x+7)-6(x+7)=0

x=6

x=-7