Solve x²+16x+64=121?

Answer 1

Factor the left hand side. This technique will work because the left hand side is a perfect square trinomial:

(x+8)(x+8)=121

(x+8)^2=121

Square root both sides (don't forget +-):

x+8=+-sqrt[121]

x+8=+-11

x=-8+-11

Thus, you have to answers:

x=-8+11=3

and

x=-8-11=-19

Hope this helps.

If you don't recognize this is possible, then your other option for solving is using the quadratic formula. That handles any quadratic equation. Just get it into the form ax^2 + bx + c:

x^2 +16x -57=0

Answer 2

Here is the easiest way to do this

x^2 + 16x + 64 = 121
(x + 8)^2 = 121
x + 8 = -11 or 11
x = -19 or 3

Answer 3

X^2 + 16X + 64 = 121

(X+8)^2 = = (+/-11)^2

X+8 = 11 or X+8 = -11

X= 3 or X= -19

---OR---

OK! Two ways:

x²+16x+64=121

x²+16x+64-121=0

x²+16x-57=0

(x + 19)(x - 3)=0

x=-19 or x=+3

Answer 4

Nightshade has a good idea, to take the square root of both sides, but there was an error in the calculations. It would go like this...
x^2 + 16x + 64 = 121 factor the left side and you get
(x + 8)^2 = 11^2 Take the square root of both sides and you get
x + 8 = +/- 11
x + 8 = 11 or x + 8 = -11
x = 3 or x = -19

Answer 5

Get each and every thing to at least one area of the equation then factorise and sparkling up. x³ + 64x = 16x² x³ - 16x² + 64x = 0 x(x² - 16x + sixty 4) = 0 x(x - 8)² = 0 x = 0 OR (x - 8)² = 0 x = 0 OR x - 8 = 0 x = 0 OR x = 8

Answer 6

x^2 + 16x + 64 = 121
(X^2) + (2*8*x) + (8)^2 = (11)^2
(x + 8)^2 = (11)^2
x+8 = 11
X = 3

Answer 7

Subtract 121 on both sides:
x^2+16x-57=0
(x-3)(x+19)=0
x-3=0
x+19=0
x=3 and -19

Answer 8

x=3 or 19

Answer 9

x²+16x+64=121
(x+8)^2=121
x+8=+/-11
x=-19
x=3

Answer 10

Take the sqrt of everything.
x+4x+8=11
Combine liek terms
5x+8=11
Isolate the variable
5x=3
x=3/5