what is the gcf of 16s³t, 40s⁵, and 68t²?\n4\n4s³t\n8\n8s³t

Explanation:

Step1: Prime - factor the coefficients

$16 = 2\times2\times2\times2$, $40 = 2\times2\times2\times5$, $68 = 2\times2\times17$. The GCF of 16, 40 and 68 is $2\times2=4$.

Step2: Analyze the variables

For the variable $s$, the powers of $s$ are $s^{3}$ in $16s^{3}t$, $s^{5}$ in $40s^{5}$ and there is no $s$ in $68t^{2}$. The lowest - power of $s$ among them is $s^{0}$ (since there is no $s$ in the third term), so $s$ is not part of the GCF. For the variable $t$, the powers of $t$ are $t^{1}$ in $16s^{3}t$, $t^{0}$ in $40s^{5}$ and $t^{2}$ in $68t^{2}$. The lowest - power of $t$ is $t^{0}$, so $t$ is not part of the GCF.

Answer:

A. 4