Does the community property of addition apply want to add to negative integers

Find the angle between each of the following pairs of vectors A⃗ = Axi^+Ayj^ and B⃗ = Bxi^+Byj^ ... Ax1 = - 3.20, Ay1 = 4.40; Bx1 = 2.70, By1 = - 3.10. i know this is dot prodoct but the calculater just keep saying error

How many solutions does the system of equations have x-2y=6 and 3x-6y=18

You are painting the outside of a 28-foot fence that goes around a square garden. There are 4 equal sections. You have painted 12 of one section. What fraction of the job have you completed?

A jersey is on sale for 50% off the original price. A week later, the manager takes another 50% off. Is the jersey now free.

If y=4x 5, find the value of y when x=0

Param needs 375 g of chocolate chips for one batch of cookies. He has two 2-kg bags of chocolate chips. Does Param have enough chocolate chips to make 12 batches of cookies? Explain. * keep in mind there are 1000 grams in 1 kilogram.

Is 89 a prime number

What+8,477.6=10,248 what+0.07=0.1

Farmer Joe has a rectangular pasture that is fenced in for his cattle. He bought some horses and wants to cut the pasture in half diagonally from corner to corner.

Y=sinx^cosx cosx^sinx dy/dx=?