x^2 + 8x + 9 = -7?

Find two factors of 16 that, when added together, give 8. Only 4 and 4 do this.

x² + 8x + 16 = 0

(x+4)(x+4) = 0

x=-4

x^2 + 8x + 9 = -7 upload 7 to the two factors of = x^2 +8x + 9 + 7 = 0 combine like phrases x^2 + 8x + sixteen = 0 factor. understand that 4+4 = 8 and four * 4 = sixteen, hence: (x + 4)(x+4) = 0 So: x+4 = 0 sparkling up for x x = -4

x^2 + 8x + 9 = -7
x^2 + 8x + 9 + 7 = 0
x^2 + 8x + 16 = 0
x^2 + 8x + 16 = (x + 4)(x + 4)
(x + 4) = 0
x = -4 (repeated)

x^2 + 8x + 9 = -7
x^2 + 8x + 9 + 7 = 0
x^2 + 8x + 16 = 0
x^2 + 4x + 4x + 16 = 0
x(x + 4) + 4(x + 4) = 0
(x + 4)(x + 4) = 0

x + 4 = 0
x = -4

∴ x = -4

x^2+8x+9=-7
x^2+8x+9+7=0 (brought seven to other side)
x^2+8x+16=0
factor it out:
(x+4)(x+4)=0
x+4=0 , x+4=0
therefore x=-4, x=-4
x= -4, -4

Looks like it's "Let's do Darius W's homework" day.

x² + 8x + 9 = -7

Add 7 to both sides:

x² + 8x + 16 = 0

Factor:

(x + 4)² = 0

x + 4 = 0
x = -4

just a small note, another way to write x= -4,-4 is x = -4, dbl (double) in case your teacher cares.