Cho tập hợp X={-3;-2;0;1;2}. Trên X xác định quan hệ S như sau: (a;b) ∈ ↔ a2- b2= a-b,∀a;b∈X
Chứng minh rằng S có tính chất đối xứng

This is different from the first one can someone me

Angle xyz is formed by segments xy and yz on the coordinate grid below: a coordinate plane is shown. angle xyz has endpoints at 3 comma negative 1 and 6 negative 2 and 3 comma negative 3 and measures 36.87 degrees. angle xyz is rotated 270 degrees counterclockwise about the origin to form angle x′y′z′. which statement shows the measure of angle x′y′z′?

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.