Question

x² +y²+ z² = 14 & XY + YZ+ ZX = 11 then ( x + y + z)²=? ​

Answer 1

Answer:

$(x + y + z) {}^{2} { = } x ^{2} + y{}^{2} + z {}^{2} + 2(xy + yz + zx)$

STEPS

USING THE ABOVE FORMULA

$(x + y + z) {}^{2} = 14 + 2(11) \\ =14 + 22 \\ = 36$