We need 2880 person-hours and we have 12 people.
When we divide the work between them: 2880/12 = 240 hours required to complete.
If the second equation is y=-3x+4 then they would be parallel and I found that by turning the first equation into y=mx+b and you subtract x from both sides of the equation and get -3y=-x+15 and then you divide both sides of the equation by -3 to get the y by itself and that turns into y=1/3x-5 and since 1/3 is the reciprocal of -3 they are perpendicular.
Slope intercept form is y=mx+b
y=-x+700
-8 = trevon
(3/4)-8 = beth
= -6
1/4[(3/4)-8] = leah
1/4(-6)
= -1.5