Question

Please help me simplify the expression

Answer 1

Answer:

$-21s^{3}$

Step-by-step explanation:

$-3s^{2} \times 7s$

$-21s^{2+1}$

$-21s^{3}$

Answer 2

Answer:

$-21s^3$

Step-by-step explanation:

multiply the coefficients of the two expressions to get a coefficient of -21

then multiply the variables, adding the exponents (2 and 1) and using 3 as the exponent of the result