Elitmus
Exam
Numerical Ability
Algebra
How many solutions exists for √(x+5) = x√(x+5)
a.1
b.2
c.3
d.4
Read Solution (Total 12)
-
- b. 2
√(x+5) = x√(x+5)
=> √(x+5) - x√(x+5) = 0
=> √(x+5)*(1-x) = 0
=> (x+5) = 0 or (1-x)= 0
=> x = 1, -5
if squaring is done then u will get three roots x = -1, 1, -5
but x= -1, doesn't satisfy the given eqn
so, two soln esist.
- 10 years agoHelpfull: Yes(48) No(3)
- c.3
√(x+5) = x√(x+5)
on squaring both sides we will get
(x+5)=x^2(x+5)
on rearranging the eqution,we will get
=>x^2(x+5)-(x+5)=0
=>(x+5)(x^2-1)=0
=>either (x+5)=0 or (x^2-1)=0
=>hence,x can be -5,1,-1
so there will be three solutions - 10 years agoHelpfull: Yes(12) No(11)
- ans is 2...
√(x+5)-x√(x+5)=0
take √(x+5) common n there will be two sol for x - 10 years agoHelpfull: Yes(2) No(2)
- Given, sqrt(x+5) = x sqrt(x+5)
Squaring both sides we get:
(x + 5) = x^2(x + 5)
=> x^2(x + 5) - (x + 5) = 0
=> (x^2 - 1)(x + 5) = 0
=> x = 1, -1, -5
so When x = 1:
sqrt(x+5) = x sqrt(x+5)
=> sqrt(1+5) = 1 xx sqrt(1+5)
=> sqrt(6) = sqrt(6) (which is true)
When x = -5:
sqrt(x+5) = x sqrt(x+5)
=> sqrt(-5+5) = -5 xx sqrt(-5+5)
=> sqrt(0) = -5 * sqrt(0)
=> 0 = 0 (which is true)
When x = -1:
sqrt(x+5) = x sqrt(x+5)
=> sqrt(-1+5) = -1 xx sqrt(-1+5)
=> sqrt(4) = -sqrt(4)
=> 2 = -2 (which is not true)
So for the given equation we can have two values of x. - 7 years agoHelpfull: Yes(2) No(0)
- 2,(x+5)=x^2(x+5)=>x^2=1
- 10 years agoHelpfull: Yes(0) No(0)
- c.3
Nobody said x can't be 0
The solutions are x = 0,1,-5 - 10 years agoHelpfull: Yes(0) No(10)
- no of soutions will be 2
- 10 years agoHelpfull: Yes(0) No(0)
- There are three solutions but 2 satisfies the condition hence ans is 2
- 10 years agoHelpfull: Yes(0) No(0)
- c.3
√(x+5) = x√(x+5)
on squaring both sides we will get
(x+5)=x^2(x+5)
on rearranging the eqution,we will get
=>x^2(x+5)-(x+5)=0
=>(x+5)(x^2-1)=0
=>(x+5)(x-1)(x+1)=0
=> 3 solutions
- 9 years agoHelpfull: Yes(0) No(2)
- 4 sol:arrange as per data.i get 4
- 9 years agoHelpfull: Yes(0) No(2)
- ans is 2
on squaring both side we get
x+5 = x^2(x+5)
=> x^2 = 1
=> x =+-1
- 9 years agoHelpfull: Yes(0) No(2)
- ans b
√(x+5) = x√(x+5)
take square both side
then
(x+5)=x^2(x+5)
solve it we find
x^2=1
then
x=1,x=-1
we put the value of x in the equation
and satisfy these value
and there are solution
- 9 years agoHelpfull: Yes(0) No(1)
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