Question

If a² + b ² + c ² = 770 and a+b+c=15, then
find the value
of ab + bc+ca.​

Answer 1

.......THANKU........

Answer 2

Answer:

(-545)/2

Step-by-step explanation:

a²+b²+c²+2(ab+bc+ca)=(a+b+c)²

770+2(ab+bc+ca)=(15)²

770+2(ab+bc+ca)=225

2(ab+bc+ca)=225-770

ab+bc+ca=(-545)/2