Question

Multiply the polynomials:

$\left(i\right)(2.5a-0.5b)and(4b^2-8ab)$

$\left(ii\right)\left(\frac{1}{9}\right)a^2+bc-15and\left(\frac{4}{7}\right)b^2+ab+10$ [2 MARKS]

Answer 1

Application: 1 Mark each

$\left(i\right)(2.5a-0.5b)and(4b^2-8ab)$

$=10a{b}^2-20a^{2}b-2b^3+4a{b}^2$

$=14a{b}^2-20a^{2}b-2b^3$


$\left(ii\right)(\frac{1}{9}{a}^2+bc-15)(\frac{4}{7}{b}^2+ab+10)$

$=\frac{4}{63}{a}^2{b}^2+\frac{1}{9}{a}^{3}b+\frac{10}{9}{a}^2+\frac{4}{7}{b}^{3}c+a{b}^{2}c+10bc-\frac{60}{7}{b}^2-15ab-150$