35.6 minutes
S = v*t = 8 * 40/60 = 16/3 m
=> t = s/v = 16/(3*9) = 35.555555 minutes
1 (8/9) = 1.88888888
3 (11/12) = 3<span><span>.9166666667
</span>
</span>
3<span>.91666 / </span>1.8888 =
<span>
<span>
<span>
2.0735294118
</span>
</span>
</span>
So, she can make 2 batches of cupcakes.
Since <span><span>−y</span></span> does not contain the variable to solve for, move it to the right side of the equation by adding <span>y</span> to both sides.<span>x=<span>y+<span>30</span></span></span>