For natural numbers a and b, $(a+b)^2- (a - b)^2>29$ and the smallest value of ab is m. The value of $(m^2+m+1)$ is
Answer & explanation
Correct answer: option 4
$(a+b)^2- (a - b)^2>29$
a2 + b2 + 2ab - a2 - b2 + 2ab > 29
4ab > 29
If 4ab is greater then 29 then it must be the multiple of 4 more than 29
So we can take the value of 4ab = 32
then, ab = 8 = m
Now, $(m^2+m+1)$ = $(8^2+8+1)$ = 73