Solve 7y(?-?)=-14xy+21: Finding Missing Terms in Linear Equations

To solve this problem, we need to factor both sides of the equation $7y(?-?) = -14xy + 21$.

First, observe the terms on the right-hand side: $-14xy$ and $21$.

• Both terms share a common factor of 7. Factoring out 7 from both terms yields:

$7(-2xy + 3)$.

Thus, the expression becomes:

$7y(-2x + \frac{3}{y})$ since the y was outside the parenthesis in the left.

Matching terms with $7y(? - ?)$, the missing values are $\frac{3}{y}$ and $2x$.

Therefore, the solution is: $\frac{3}{y}, 2x$, corresponding to the correct choice.