Answer
1st blank: $1$
2nd blank: $2$
3rd blank: $10$
Work Step by Step
To find the first blank, you subtract $9y^{2}$ $-$ $8y^{2}$. You get $1y^{2}$. But because after the blank there is already a $y^{2}$, the answer is just $1$.
To find the second blank, you subtract $2y$ $-$ $4y$. That gets you $-2y$. But because there is already a $-$ before the blank, the answer is just $2$.
To find the third blank, you subtract ($7$) $-$ ($-3$). That is the same as $7$ $+$ $3$. So you get $10$.
