114k views
3 votes
X^2 - 2x - 63 = 0

Which value is a solution to the given equation?
A:-7
B:-2
C:0
D:63

User Samir
by
5.0k points

1 Answer

7 votes

Step-by-step explanation: When an equation has a squared term in it

such as x² - 2x - 63 = 0, it's called a polynomial equation.

The rule for solving a polynomial equation is

to first set it equal to 0, them factor.

Since this equation is already set equal to 0, we can factor the left side.

To factor x² - 2x - 63, look for factors of -63 that add to -2.

In this case, these factors are -9 and +7.

So we have (x - 9)(x + 7) = 0.

When two terms are multiplying together to equal 0,

either one term or the other must equal 0.

So x - 9 = 0 or x + 7 = 0.

Solving for x in each equation, we get x = 9 or x = -7.

So this equation has two solutions and we write out answer

in set notation which looks like this {9, -7}.

User Peter Bartels
by
5.3k points