Question

a+b=10. a²+b²+c²=36. then what is ab+bc+ca​

Answer 1

answer

$(a + b + c) {}^{2} = a {}^{2} + b {}^{2} + c {}^{2} + 2(ab + bc + ca) \\ (10) {}^{2} = 36 + 2(ab + bc + ca) \\ 100 - 36 = 2(ab + bc + ca) \\ \frac{64}{2} = ab + bc + ca \\ 32 = ab + bc + ca$

Answer 2

The question is wrong and can't be solved. The reason is not enough data given.

I think value of a+b+c= 10 instead of just a+b