93.2k views
5 votes
Solve the quadratic equation by completing the square.

x2 + 8x + 19 = 0
What’s the answer ? Math algebra 2

User Pjetr
by
4.3k points

1 Answer

3 votes

Answer: x= 4 ±
√(-3)

Explanation:


x^(2) + 8x + 19 = 0 First subtract 19 from both sides

-19 -19


x^(2) + 8x = -19 Now to complete the square on the left side you will divide 8 by 2 and square the number that you will get and add it to both sides. If you divide 8 by 2 you get 4 and 4 squared is 16 .So add 16 to both sides.

x^2 + 8x + 16 = -19 + 16 Now factor the left side

(x+4)^2 = -3 Take the square root of both sides

(x+4) = ±
√(-3)

Subtract 4 from both sides

x = ±
√(-3) - 4

User Little Santi
by
4.1k points