Answer
a. 15$x^{14}$
b. -56c$d^{2}$
c. $\frac{12j^{3}}{k^{2}}$
d. $x^{a+b+c}$
Work Step by Step
a. 5$x^{4}$$\times$$x^{9}$$\times$3x = (5$\times$3)($x^{4+9+1}$) = 15$x^{14}$
b. -4$c^{3}$$\times$7$d^{2}$$\times$2$c^{-2}$ = $\frac{(-4\times7\times2)(c^{3}d^{2})}{c^{2}}$ = (-56)($d^{2}$)($c^{3-2}$) =- 56c$d^{2}$
c. $j^{2}$$\times$$k^{-2}$$\times$12j = $\frac{12j^{2+1}}{k^{2}}$ = $\frac{12j^{3}}{k^{2}}$
d. $x^{a}$$\times$$x^{b}$$\times$$x^{c}$= $x^{a+b+c}$
