Question

If a+b-c= 7 and ab-bc-ca = 4 find a^2+b^2+c^2​

Answer 1

$\sf \frak \red{Answer:-}$

Formula used:

• (a+b-c)²=a²+b²+c²+2(ab-bc-ca)

Solution:

(a+b-c)²=a²+b²+c²+2(ab-bc-ca)

=> (7)²= a²+b²+c²+2*4

=> 49-8=a²+b²+c²

=> 41 = a²+b²+c²

$\rm{ \therefore \purple{a²+b²+c²=41}}$