There are 2 parts to it . part a and part b .

2x^{2} - y^{2} +5xy - 2y

A) 4 terms

B) 0 negatives

Step-by-step explanation:

Combine the like terms

So -3x squared + 5x squared = 2x squared

2y squared - 3y squared = -1y squared

There is only one term with 5xy so you leave it as it is

There is only one term with 2y so you leave it as it is

Now put this in an equation and use the negative and positive signs as addition or subtraction signs.

So it looks like:

2x^{2} - y^{2} +5xy - 2y

Hoped This Helped!!!

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.