6. a boy on a jet ski spots
a helicopter at an angle of
elevation of 549. the
helicopter is flying at an
altitude of 142 feet. how
long is the line of sight
from the helicopter to the
jet ski?

When are two distinct non vertical lines parallel

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

Precalculus question, image attached.