Final answer:
To isolate 'y' in the equation 10=-5y, divide both sides by -5, resulting in y = -2.
Step-by-step explanation:
To isolate the '+y' on its own on the left-hand side of the equation 10=-5y, you need to perform the operation of division. Since y is currently being multiplied by -5, you need to do the opposite operation, which is division, to both sides of the equation to solve for y. Therefore, you would divide both sides by -5 to get y by itself.
The correct operation would look like this:
y = 10 / (-5)
When dividing by powers of 10, it's usually just a matter of moving the decimal point to the left by the number of zeros. However, since we're dividing by -5, not a power of 10, the result in this case is:
y = -2