Question

If P = 3x2 + xy - 5y? Q = 2x2 - xy + 3y2 and R = -6x2 + 4xy - 7y2?
what is P+Q-R?

Answer 1

`P+Q-R=11x^2-4xy+10y^2`

Explanation:

I'm assuming the 2's at the end of some of the terms are meant to be exponents. So here we have

`P=3x^2+xy-5y\\Q=2x^2-xy+3y^2\\R=-6x^2+4xy-7y^2`

and we're asked to find P + Q - R. Let's handle these operations left to right to cut down on clutter. Starting with P + Q, our first job should be to combine all the like terms we can. 3x² + 2x² = 5x², and xy - xy = 0, but we still can't do anything with the terms -5y and 3y². So far, this gives us

`P+Q=5x^2-5y+3y^2`

Now let's handle subtracting R from this sum. The pairs of like terms here are 5x² and -6x², and 3y² and -7y². Subtracting these parts gives us 5x² - (-6x²) = 11x² and 3y² - (-7y²) = 10y², and we can subtract off the remaing 4xy in R to give us

`P+Q-R=11x^2-4xy+10y^2`

Answer 2

is this helpful tell me please if im correct :)