Question

If a + b + C is equal to 5 and a b + BC + CA is equals to 10 then find a square + b square + c square

Answer 1

Answer:

using

${(a + b + c)}^{2} = {a}^{2} + { b}^{2} + {c}^{2} + 2(ab + bc + ca)$

put the values

${5}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2 \times 10$

therefore

${a}^{2} + {b}^{2} + {b}^{2} = 25 - 20 = 5$