Christine drives her car 144 miles and has an average of a certain speed. If the average speed has been 5 mph more, she could have traveled 168 miles in the same length of time. What was her average speed?

Let's make a system of equations:

144/x=y

168/(x+5)=y

So,

144/x=168/(x+5)

Solving using cross multiplication,

x=30

So, her average speed for driving 144 miles was 30 miles per hour.

-Hunter

sinn is the total amount of students now and m were the students before, you subtract them both (n-m) and divide that by m. then, since to get a percentage from a fraction you have to multiply by 100, your answer should look like this: n-m/m*100

step-by-step explanation:

x =-.20752

step-by-step explanation:

4^(x+2)=12

4^(x+2)=12

take the log base 4 on each side

log 4 (4^(x+2) = log 4(12)

we know log b(a^y) = y log b (a)

(x+2) log 4(4) = log 4 (12)

x+2 = log 4 (12)

we know   logb c = loga c/loga b

we want to convert to base 10   so a = 10

by default, we do not write the 10   c = 4   and b = 10

log4 10 = log 12/log 4

log4 10 = log 12/ log 4

x+2 = log 12/ log 4

subtract 2 from each side

x +2 -2 = log 12/ log 4 -2

x = 1.79248125 -2

x =-.20752