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Find the non-extraneous solutions of the square root of the quantity x plus 9 minus 5 equals quantity x plus 4

User Hilikus
by
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2 Answers

3 votes
I"m guessing you mean

√(x+9) -5=x+4
add 5 to both sides

√(x+9)=x+9
square both sides
x+9=x²+18x+81
minus x+9 both sides
0=x²+17x+72
factor
what 2 numbres multiply to get 72 and add to get 17?
8 and 9
0=(x+8)(x+9)
set to zer

0=x+8
x=-8

x+9=0
x=-9

test each


√(-8+9) -5=-8+4

√(1) -5=-4
1-5=-4
-4=-4
true


√(-9+9) -5=-9+4

√(0) -5=-5
-5=-5
true


the solutions are x=-9 and -8
User Felixhummel
by
8.5k points
1 vote

Answer:

x=8 and x=9

Explanation:

The given equation is:


√(x+9)-5=x+4

On solving this equation, we get


√(x+9)=x+9

Squaring on both sides, we get


x+9=x^2+81+18x


x^2+18x-x-9+81=0


x^2+17x+72=0


x^2+8x+9x+72=0


(x+8)(x+9)=0

Thus, the solution of the above equations are x= 8 and x=9.

User Owen Hartnett
by
8.6k points