Question

If ab + bc + ca = 42 and a2 + b2 + c2= 85, find a + b + c

Answer 1

Answer:

033_8 h5/21/23/32721*2 oy g h. u g h ibj v

Answer 2

Answer:

a + b + c = 13

Step-by-step explanation:

$ab + bc + ca = 42$

$a^{2} + b^{2} + c^{2} = 85$

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

$(a + b + c )^{2} = 85+ 2(42)$

$(a + b + c )^{2} = 85+ 84$

$(a + b + c )^{2} = 169$

$(a + b + c ) = \sqrt{169}$

$a + b + c = 13$