Question

Subtract 7x^2−5xy+8y^2 from −2x^2−15xy+9y^2

Answer 1

`y^2-10xy-9x^2`

Explanation:

We want to subtract
`7x^2 -5xy+8y^2` from
`-2x^2-15xy+9y^2`.

We set up the subtraction problem as follows:

`(-2x^2-15xy+9y^2)-(7x^2-5xy+8y^2)`.

We expand the brackets to obtain;

`=-2x^2-15xy+9y^2-7x^2+5xy-8y^2`.

We regroup the terms to obtain;

`=9y^2-8y^2-15xy+5xy-2x^2-7x^2`.

We now simplify to obtain;

`=y^2-10xy-9x^2`.