Question

If a+b=5 and a²+b²=13, then ab is equal to.​

Answer 1

Answer:

Given,

    $a+b= 5$

    $a^2 +b^2 = 13$

We know that,

    $(a+b)^2 = a^2 +b^2+2ab$

    $(5)^2 = 13 +2ab$

    $25 -13 = 2ab$

    $2ab = 12$

    $ab = \frac{12}{2}$

    $ab = 6$

          Hope it helps you^_^