This is how I'd set it up:
405/20 = 243/x
this means the mpg (miles / gallons) for 1 situation is the same as the mpg for the other situation (because the rate is the same)
then just cross multiply and solve:
405x=243*20 or 405x=4860 or x = 12
he would need 12 gallons of gas for 243 miles
2011 because it has the higher gpa of all of them
Answer:
x=-16/3 (-5.33)
Step-by-step explanation:
3(x-2)+4x=10(x+1)
3x-6+4x=10x+10
7x-6=10x+10
-6-10=10x-7x
-16=3x
x=-16/3
Answer:
Step-by-step explanation:
Using rule of exponents 
Using rule of exponents 
To equalize the negative sign, we'll move t to the denominator
