Elitmus
Exam
Sqrt(x+7)=x sqrt(x+7) what is the sum of the root of the equation
Read Solution (Total 5)
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- √(x+7)= x√(x+7)
x√(x+7) - √(x+7)=0
√(x+7) (x-1) = 0
checking possible roots ..
√(x+7)=0
x= -7
and x-1=0
x=1
sum of the roots -7 + 1= -6 - 11 years agoHelpfull: Yes(16) No(0)
- sqrt(x+7)=x sqrt(x+7)
squiring both the side
so
(x+7)=x^2 (x+7)
(x+7)=(x^3+7x^2)
x^3 - 7x^2 - x - 7 =0
x^2(x+7)-1(x+7)=0
(x^2 - 1)(x+7)=0
so their is three roots
first x+7=0 => x=-7
and x^2 - 1 =0 so x=+1 and -1
so the possible of sum = -8 or +6 - 11 years agoHelpfull: Yes(3) No(0)
- sorry in my last post i make a mistake
the possible sum of the roots= -8 or -6 - 11 years agoHelpfull: Yes(3) No(0)
- ON SQUARING......
(x^2-1)(xplus7)equal to 0
sum will be -7 - 11 years agoHelpfull: Yes(2) No(0)
- this equetion is satisfi only when
x=1 or x=-7
so sum of roots=1-7=-6 - 11 years agoHelpfull: Yes(0) No(0)
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