Question

7y³-8y²9y and 4y²-6y³-y+9
Add the following.
Answer is y^3 - 4y^2 + 8y + 9​
i need explanation

Answer 1

Answer:

y³-4y²+8y+9

Step-by-step explanation:

(7y³-8y²9y)+(4y²-6y³-y+9)

=7y³-6y³-8y²+4y²+9y-y+9

=y³-4y²+8y+9

Answer 2

Step-by-step explanation:

7y³-8y²+9y+0

-6y³+4y²+y+9

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y³-4y²-8y+9

addition rule and subtraction rule

(+) + (+) = add and put same sign

(+) + (-) = subtract nad put greater number sign

(-) + (+) = subtract and put the greater number sign

(-) + (-) = add and put the same sign