WHAT ARE THE DOMAIN AND THE RANGE OF THIS GRAPH?

Find the distance between (0,5) & (-4,2)

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.