Simplify -2r^6s^2t*-9r^3s^2t^4

$- 2 r^{6} s^{2} t \cdot - 9 r^{3} s^{2} t^{4}$

Multiply $r^{6}$ by $r^{3}$ by adding the exponents.

Move $r^{3}$ .

$- 2 (r^{3} r^{6}) s^{2} t \cdot (- 9 s^{2} t^{4})$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$- 2 r^{3 + 6} s^{2} t \cdot (- 9 s^{2} t^{4})$

Add $3$ and $6$ .

$- 2 r^{9} s^{2} t \cdot (- 9 s^{2} t^{4})$

Multiply $s^{2}$ by $s^{2}$ by adding the exponents.

Move $s^{2}$ .

$- 2 r^{9} (s^{2} s^{2}) t \cdot (- 9 t^{4})$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$- 2 r^{9} s^{2 + 2} t \cdot (- 9 t^{4})$

Add $2$ and $2$ .

$- 2 r^{9} s^{4} t \cdot (- 9 t^{4})$

Multiply $t$ by $t^{4}$ by adding the exponents.

Move $t^{4}$ .

$- 2 r^{9} s^{4} (t^{4} t) \cdot - 9$

Multiply $t^{4}$ by $t$ .

Raise $t$ to the power of $1$ .

$- 2 r^{9} s^{4} (t^{4} t^{1}) \cdot - 9$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$- 2 r^{9} s^{4} t^{4 + 1} \cdot - 9$

Add $4$ and $1$ .

$- 2 r^{9} s^{4} t^{5} \cdot - 9$

Multiply $- 9$ by $- 2$ .

$18 r^{9} s^{4} t^{5}$