What is the upper and lower bound of 0.82

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

The quadratic function h(t)=-16.1t^2+150 choose the graph representation

List the sides of δrst in ascending order (shortest to longest) if: m∠r =x+28°, m∠s = 2x+16°, and m∠t = x+12