SOLUTION: I need help solving : 5-√x+7 = √x-8
(both x+7 and x-8 are both in the square root)
The answer choices provided are:
A) {8,-7} B) 0 C) {9} D) {2}
Also, could you
Algebra ->
Square-cubic-other-roots
-> SOLUTION: I need help solving : 5-√x+7 = √x-8
(both x+7 and x-8 are both in the square root)
The answer choices provided are:
A) {8,-7} B) 0 C) {9} D) {2}
Also, could you
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Question 885409: I need help solving : 5-√x+7 = √x-8
(both x+7 and x-8 are both in the square root)
The answer choices provided are:
A) {8,-7} B) 0 C) {9} D) {2}
Also, could you please explain how the get the correct answer?
Thanks. Answer by rothauserc(4718) (Show Source):
You can put this solution on YOUR website! 5 -square root(x+7) = square root(x-8)
5 = square root(x-8) + square root(x+7)
square both sides of =
25 = (x-8) +2square root(x-8)square root(x-7) +(x+7)
25 = 2x +2square root(x-8)square root(x-7) -1
add 1 to both sides of =
26 = 2x +2square root(x-8)square root(x-7)
divide both sides of = by 2
13 = x +square root(x-8)square root(x-7)
subtract x from both sides of =
13-x = square root(x-8)square root(x-7)
use square root rule, square root(ab) = square root(a)squar root(b)
13-x = square root((x-8)(x+7))
square both sides of =
169-26x-x^2 = (x-8)(x+7)
169-26x-x^2 = x^2-x-56
-25x = -225
x = 9
answer is C
