Question

show how to solve:
√x+2+4=x

Answer 1

\[\sqrt{x+2}+4=x\]

Answer 2

is this your question??

Answer 3

yes

Answer 4

id try to get the sqrt part all by itself then undo it by squaring both sides

Answer 5

@TiaW

Answer 6

yes??

Answer 7

squaring the equation does introduce a "false" result which would have to be determined at the end of the setup

Answer 8

(√x+2)(√4)

Answer 9

@03453660 yes?

Answer 10

ok coming to you

Answer 11

ok

Answer 12

wait.. waat?

Answer 13

i know its 7. but i dont know how to get it

Answer 14

√(x+2) + 4 = x to get the sqrt all alone, we would have to subtract off 4 right?

Answer 15

yeah

Answer 16

√(x+2) + 4 = x
- 4 -4
---------------
√(x+2) = x -4


to undo a sqrt, we need to square it

Answer 17

[√(x+2)]^2 = (x -4)^2

x+2 = (x - 4)^2

can you expand the right side of this?

Answer 18

nope. im lost

Answer 19

at what point did you get lost at?

Answer 20

never mind. i was lookin at it wrong.. so it'll be:
x+2 = (x - 4)^2
x+2=x^2+16
x=x^2+14
x-x2=14??

Answer 21

something like that yes, but i think there are a few missteps along the way

x+2 = (x - 4)^2

x+2 = x^2 - 8x +16
-x - x
-------------------
2 = x^2 - 9x +16
-2 -2
-----------------
0 = x^2 -9x +14

Answer 22

there are different ways that we can solve a quadratic; factoring might be a good method for this.

2 numbers that add to -9
and multiply to 14 ; -7 and -2

(x-7)(x-2) = 0 ; when x=7 or x=2

Answer 23

where 8x come from?

Answer 24

the most used method for this is the "foil" method; which is a memory aid for firsts lasts outsides insides