Set up a proportion. 2/5 = x/40
to solve the equation first cross multiply.
x*5=40*2
x*5=80
now divide both sides by 5, 80 divided by 5 is equal to 16.
so the number of girls in the computer lab is 16.
There 6 possible outcomes for a roll of a die. So if there are two dice, then it's 
You don't see any y values that are the same, so you have to write the equations first
equation 1: the slope is m=(14-2)/(3-0)=4, and the y intercept is 2 (you can tell from the point (0,2)) so the equation is: y=4x+2
equation 2:
your last pair of x and y are not correct. they must be 3, -3 instead, not 3, 3
the slope is m=[(-3-(-12)]/(3-0)=3, and the y intercept is -12, so the equation is y=3x-12
solve the system of equation: y=4x+2 and y=3x-12
4x+2=3x-12
x=-14
y=3x-12=3*(-14)-12=-54
so the answer is (-14, -54)
