Question

Write 5 examples of the form (a + b + c)² and expand them using the formula.

Answer 1

Expressions of the form (a + b + c)² are:

(1) ${\left(a+5b+3c\right)}^2=a^2+25b^2+9c^2+10ab+30bc+6ca$
(2) ${\left(-4a+2b+c\right)}^2=16a^2+4b^2+c^2-16ab+4bc-8ca$
(3) ${\left(a+3b+7c\right)}^2=a^2+9b^2+49c^2+6ab+42bc+14ca$
(4) ${\left(3a-4b-6c\right)}^2=9a^2+16b^2+36c^2-24ab+48bc-36ca$
(5) ${\left(a-7b+3c\right)}^2=a^2+49b^2+9c^2-14ab-42bc+6ca$