Question

a的平方加b的平方加c的平方等于14,且ab加bc加ac等于11,求a加b加c的值

Answer 1

a^2+b^2+c^2=14,

ab+bc+ac=11,

(a+b+c)^2

=a^2+b^2+c^2+2ab+2bc+2ac

=14+22

=36

a+b+c=6,-6