Answer:
<u>Part A: </u>
<u>n = 5q (1st equation)</u>
<u>0.05n + 0.25q = 2 (2nd equation)</u>
<u>Part B:</u>
<u>q = 4 ⇒ n = 5 * 4 = 20</u>
<u>Part C:</u>
<u>Margie has 20 nickels and 4 quarters, for a total of $ 2.00</u>
Step-by-step explanation:
Let's recall that a nickel has a value of $ 0.05 and a quarter a value of $ 0.25.
Let n represent the number of nickels and q represent the number of quarters.
Part A:
Write a system of equations to represent the situation.
n = 5q (1st equation)
n * 0.05 + q * 0.25 = 2
0.05n + 0.25q = 2 (2nd equation)
Part B:
Replacing n in the 2nd equation to solve for q:
0.05n + 0.25q = 2
0.05 * 5q + 0.25q = 2
0.25q + 0.25q = 2
0.5q = 2
q = 2/0.5
<u>q = 4 ⇒ n = 5 * 4 = 20</u>
<u>Part C:</u>
<u>Margie has 20 nickels and 4 quarters, for a total of $ 2.00</u>
Answer: approximately 49
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
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Answer:
30 and 9
Step-by-step explanation:
x+y=39 , x-y=21
Solve for x:
x+y=39 , x-y=21
x= 30
Substitute x with 30:
(30)+y=39 , (30)-y=21
Solve for y:
y=9
<span>We can safely assume that 1212 is a misprint and the number of seats in a row exceeds the number of rows by 12.
Let r = # of rows and s = # of seats in a row.
Then, the total # of seats is T = r x s = r x ( r + 12), since s is 12 more than the # of rows.
Then
r x (r + 12) = 1564
or
r**2 + 12*r - 1564 = 0, which is a quadratic equation.
The general solution of a quadratic equation is:
x = (-b +or- square-root( b**2 - 4ac))/2a
In our case, a = 1, b = +12 and c = -1564, so
x = (-12 +or- square-root( 12*12 - 4*1*(-1564) ) ) / 2*1
= (-12 +or- square-root( 144 + 6256 ) ) / 2
= (-12 +or- square-root( 6400 ) ) / 2
= (-12 +or- 80) / 2
= 34 or - 46
We ignore -46 since negative rows are not possible, and have:
rows = 34
and
seats per row = 34 + 12 = 46
as a check 34 x 46 = 1564 = total seats</span>
