Answer:
A. 38
Step-by-step explanation:
Let d = number of dimes.
Let n = number of nickels.
First equation:
There are twice as many dimes as nickels. The number of dimes is 2 times the number of nickels. The first equation is:
<em>d = 2n</em>
Second equation:
The value of a dime is $0.10. The value of a nickel is $0.05. The value of d number of dimes is 0.1d. The value of n number of nickels is 0.05n. The total value of d dimes and n nickels is 0.1d + 0.05n. We are told the total value of her dimes and nickels is $4.75. That gives us the second equation:
<em>0.1d + 0.05n = 4.75</em>
We have two equations and two unknowns, so we can answer this question by solving a system of two equations in two unknowns.
d = 2n
0.1d + 0.05n = 4.75
We will use the substitution method.
Since d = 2n, replace d in the second equation with 2n.
0.1(2n) + 0.05n = 4.75
0.2n + 0.05n = 4.75
0.25n = 4.75
n = 4.75/0.25
n = 19
Now that we know the number of nickels, we use the equation d = 2n to find the number of dimes.
d = 2n
d = 2 * 19
d = 38
Answer: Debra had 38 dimes.
Answer:
1 inch = 0.3 miles
Step-by-step explanation:
We basically want to know how many miles in real life 1 inch on the map represents. We already know that 4 inches on the map corresponds to 1.2 miles in real life, but we need to find what 1 inch on the map corresponds to. Let's make a proportion:
Cross-multiply:
4x = 1.2
Divide by 4 from both sides:
x = 1.2/4 = 0.3
Thus, the scale is 1 inch = 0.3 miles.
Hope this helps!
Answer:
3
Step-by-step explanation:
9 / 54 = x / 18
x = 3
