Find the slope of the line that passes through (-2, 8) and (-10, 14)

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?

Abox of chocolates costs $7. which equation relates the number of boxes sold (x) and total cost of the boxes sold (y)?

Need solving this second acceleration problem.