Question

WIll fan and medal!

Solve the following equation:
\sqrt{x+4}=3x-12

Answer 1

x = 5

Answer 2

but how?

Answer 3

you could graph it or solve the equation

Answer 4

i uh, need help with the steps to solve the equation :P

Answer 5

okay work me through what you have done so far

Answer 6

\[\left( \sqrt{x+4}^2 \right) = \left( 3x-12 \right)^2\]
x+4 = 9x - 144

Answer 7

your close, you made a mistake simplifying the right hand side of your equation, it should be: (3x-12)(3x-12)

Answer 8

k, so i got x + 4 = 9x^2 - 72x + 144

Answer 9

good

Answer 10

now subtract 4 and x from both sides

Answer 11

so you get 0 on the left hand side of your equation

Answer 12

0 = 9x^2 - 72 + 140

Answer 13

and then i graph that?

Answer 14

nope you made a mistake

Answer 15

where did i go wrong..?

Answer 16

remember you have to foil

Answer 17

it should be: 0 = 9x^2 - 73x + 140

Answer 18

you forgot to subtract the x

Answer 19

then all you have to do is plug it into the quadratic formula

Answer 20

\[x = \frac{-73\pm \sqrt{(-73)^2 - 4 (9) (140)}\ }{ 18 }\]

Answer 21

k, that;s how far i got

Answer 22

yup now solve both the equations with the + and the -

Answer 23

i keep on getting fractions as answer when i type it in the calc..

Answer 24

one awnser should be a fraction

Answer 25

the other should be 5

Answer 26

i got -5...

Answer 27

nope its 5

Answer 28

lol alright :) thanks for your help!