Which of the following equations has a solution of -50? a)b - (20) = -30 b)-2r = 50 c)x/2= -25 d)n + (-16) = 65

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Square a has a side length of (2x-7) and square b has a side length of (-4x+18). how much bigger is the perimeter of square b than square a?and show all work! you so