75 elves.
I created a fraction to help solve for the number of elves. I did so by:
90/x=140/210
I solved for x which would equal 135. This is the equivalent number of elves in the theater. You would subtract this number from 210 which would equal 75.
OR
You can figure out how many elves equal 1 giant. In this case, you would divide 210 by 140 which equals 1.5 giants. Since there are 90 giants, you multiply 1.5 giants to find out an equivalent for elves which would equal 135. Same as before, subtract this from 210, resulting in 75.
Answer:
C) $10,000 invested at 6.7% compounded quarterly over 7 years yields the greater return.
Step-by-step explanation:
-We determine the effective interest rate in both scenarios and use it to calculate the investment's value after 7 years.
#Given n=7yrs, P=$10,000 and i=6.6% compounded monthly:

#Given n=7rs, P=10000, i=6.7%

Hence, the investment has the largest value($15,921.75) when the interest rate is compounded quarterly.
Answer:
3x+4 Ralph is currently 12 years old.
Step-by-step explanation:
You can find the equation by reading the scenario given. When you read it, it says that Ralph is 3 times as old as Sara and since her current age is going to be used to represent x you will first get 3x. That automatically eliminates the second and third choice given. It then says the equation is for Ralph's age in four years which means to add four to the equation. This gives you 3x+4 as your equation.
When something is tripled and then in a few years it is doubled, it is easiest to first try the number that is being added. So in this case the number is four. When you multiply 4 by 3 you get 12. If Sara is 4 she'll turn eight in four years and if Ralph is 12 he'll turn 16 in four years. 16 divided by 2 is 8 which shows you that Ralph is currently 12
Answer:
x=-1
Step-by-step explanation:
y=4x+10
y=3x+9
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4x+10=3x+9
4x-3x=9-10
x=-1