Radical Equations..got part of it

[candy101]

ok i got this question i don't understand how the teacher got the -32x

2x+ square root ?x+1 = 8

i know i have to move the the 2 x over and then square everything


this is the answer i am getting ===> x+1 = 64 + 4x

but the teacher got ==> x+1= 64 -32x + 4x


thanks

 

[wjm11]

ok i got this question i don't understand how the teacher got the -32x

2x+ square root ?x+1 = 8

i know i have to move the the 2 x over and then square everything


this is the answer i am getting ===> x+1 = 64 + 4x

but the teacher got ==> x+1= 64 -32x + 4x

You did not square the right hand side correctly. You cannot just square the individual terms. You need to "FOIL".
Example: (a + b)^2 does not equal a^2 + b^2.
(a + b)^2 = (a + b)(a + b) = a^2 + 2ab + b^2

So

(8 - 2x)^2 = (8 - 2x)(8 - 2x) = 64 - 16x -16x + 4x^2 = 64 - 32x + 4x^2

 

[candy101]

oh i c...


thank you so very much! hugs