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:
y = 3/4 or y = -3/5
Step-by-step explanation:
Solve for y:
(8 y - 6) (10 y + 6) = 0
Hint: | Find the roots of each term in the product separately.
Split into two equations:
8 y - 6 = 0 or 10 y + 6 = 0
Hint: | Look at the first equation: Factor the left hand side.
Factor constant terms from the left hand side:
2 (4 y - 3) = 0 or 10 y + 6 = 0
Hint: | Divide both sides by a constant to simplify the equation.
Divide both sides by 2:
4 y - 3 = 0 or 10 y + 6 = 0
Hint: | Isolate terms with y to the left hand side.
Add 3 to both sides:
4 y = 3 or 10 y + 6 = 0
Hint: | Solve for y.
Divide both sides by 4:
y = 3/4 or 10 y + 6 = 0
Hint: | Look at the second equation: Factor the left hand side.
Factor constant terms from the left hand side:
y = 3/4 or 2 (5 y + 3) = 0
Hint: | Divide both sides by a constant to simplify the equation.
Divide both sides by 2:
y = 3/4 or 5 y + 3 = 0
Hint: | Isolate terms with y to the left hand side.
Subtract 3 from both sides:
y = 3/4 or 5 y = -3
Hint: | Solve for y.
Divide both sides by 5:
Answer: y = 3/4 or y = -3/5
Answer:
AC is four times longer than DF
Step-by-step explanation:
AC is the diameter of the circle E and DE is the radius of the circle E
AC = 2 x DE
DE is the diameter of the circle F and DF is the radius of the circle F
DE = 2 x DF
AC = 2 x DE
AC = 2 x (2 x DF)
AC = 4 x DF
So AC is four times longer than DF
Answer:
you did not tell us what to calculate in the question
About eight pounds.
You divide 20 by 5, which is four. You then multiply 4 by the amount of pounds (2).
Hope that helps
