Pl answer quick

x+3y=-3
find x and y

Which triangle congruence postulate or theorem justifies my claim that the steps i made using construction paper and scissors produce an isosceles triangle? was it sss, sas, asa, aas, or hl?

The difference between two numbers is one. three times the larger number minus two times the smaller number is 9. what are the two numbers

What is the greatest number of parts of a circle that can be formed by cutting the circle with 7 straight cuts? (note: the parts do not have to be equal in size)