Question

PLSS HELP ME OUT....

Answer 1

Don't mind about the handwriting.

Answer 2

$we \: know \: that \\ {(a + b + c)}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2(ab + bc + ca) \\ {12}^{2} = 100 + 2(ab + bc + ca) \\ \frac{144 - 100}{2} = ab + bc + ca \\ ab + bc + ca = 22......answer$