Numbers that are east to compute with mentally are called

At a point on the ground 50 meters from the foot of a tree, the angle of elevation to the tree is 48°. find the height of the tree to the nearest meter.

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

Isabel graphed the following system of equations. 2x – y = 6 y = -3x + 4 she came up with the solution (2,-2). what were the 3 steps she did to get that solution? (make sure they are in the correct order)