Question
Quantitative Aptitude Question on Number of integer solutions
The number of integer solutions of the equation (x2−10)(x2−3x−10)=1 is
The correct answer is: 4
For the given equation, we have:
(x2−10)(x2−3x−10)=1
Since any non-zero number raised to the power of 0 is 1,we can immediately see that one possible solution is when the base (x2−10) is equal to 1:
x2−10=1
x2=11
This gives us two solutions for x:x=11andx=−11.
Now,let's consider the case where the exponent (x2−3x−10) is equal to 0:
x2−3x−10=0
This is a quadratic equation that can be factored:
(x-5)(x+2)=0
This gives us two more solutions: x=5 and x=-2.
However,we need to check whether these solutions satisfy the original equation:
For x=11andx=−11:
(x2−10)(x2−3x−10)=(11−10)0=10=1
For x = 5 and x = -2:
(x2−10)(x2−3x−10)=(25−10)(25−3(5)−10)=150=1
All four solutions satisfy the given equation, so the total number of integer solutions is 4: x=11,x=−11,x=5, and x = -2.