What algebraic expression must be subtracted from y2+5y-1 and 3y2-2y+4 to give you the sum of 2y2+7y-2

Step-by-step explanation:

The complete exercise is: "What algebraic expression must be subtracted from the sum of and to give as the result?"

For this exercise it is necessary to remember that a sum is the result of an addition. Then, if you need to find the sum of and , you need to add them by combining the like terms.

You also need to remember the multiplication of signs:

So, you get that the sum of those expression is the following:

Since you must find the algebraic expression asked in the exercise, you need to subtract the expression  from that sum calculated above.

Therefore, you get:

Then, the algebraic expression asked is: