Question

a+b+c=15 and ab+bc+ca=25, find a^2+b^2+c^2

Answer 1

Answer:

175

Step-by-step explanation:

We have (a+b+c)2=a2+b2+c2+2(ab+bc+ca). So,

152=a2+b2+c2+2(25)

225=a2+b2+c2+50

∴a2+b2+c2=225−50=175

Answer 2

Answer:

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

152 = a^2 + b^2 + c^2 + 2(25)

225 = a^2 + b^2 + c^2 + 50

a^2 + b^2 + c^2 = 225 - 50

a^2 + b^2 + c^2 = 175