Question

if a+b=7 and ab=12, then find the value of a 2 -ab+b 2

Answer 1

answer is 13..... hope u like it

Answer 2

13 is the value of $\bold{a^2-ab+b^2}$

Given:

$a+b=7 \\ab=12$  

To find:

The value of $a^2-ab+b^2=?$

Solution:

From the given  

$a+b=7 \\ab=12$

To find the value of $a^2-ab+b^2$ first express the term in to value given and then substitute the values and simplify it.

The value of the term $a^2-ab+b^2$ can be found.

$a^2-ab+b^2=a^2+2ab-3ab+b^2$

Using the identity $\bold{a^2+2ab+b^2=(a+b)^2}$

                         $=(a+b)^2-3ab$

Substituting the given value

 $=(7)^2-3(12)\\ =49-36=13$

Therefore, the value of$\bold{a^2-ab+b^2}$ is 13. If $a+b=7$ and $ab=12.}$