My math final is tomorrow and I can't figure out how to do proportions with variables. I am allowed to use a calculator so that will be ok.
I really need help studying for my math final. I need help solving proportions with variables.
Proportions compare 2 things. For instance, if a questions asks how many cows can graze on 60 acres of a land if 15 cows can graze on 3 acres of land, we set up the proportion as cows : acres
15 : 3 = x : 60
Then convert the equation to a fraction:
___ = ___
Next, cross multiply by multiplying the numerator on one side of the equal sign by the denominator on the other side of the equal sign:
15*60 = 3x
900 = 3x
Divide both sides of the equal sign by 3 to isolate x
900/3 = 3x/3
300 = x