Hey I need some help setting up these two algebra word probelms:
A combination of quarters and dimes equals $1.65. If there are 6 more dimes than there are quarters, how many coins of each are there?
And:
Roses are sold for $3.50 per dozen and carnation are sold for $2.50 per dozen. If the florist sold 14 dozen and $43, how many dozen of each flower did the florist sell?
Thanks. :-)
Word Problem Help?
Let q = number of quarters
Let d = number of dimes
0.25 * q = the worth of the quarters
0.10 * d = the worth of the dimes
0.25 * q + 0.10*d = the total worth of quarters and dimes
0.25 * q + 0.10*d = 1.65 %26lt;========= from problem
6 more dimes than quarters means you have to multiply the number of QUARTERS by 6 to equal the number of dimes
6q = d %26lt;=== OOPS! I READ THE PROBLEM AS 6 TIMES MORE AND NOT 6 MORE. This should be d - 6 = q
SO SORRY FOR THE MISTAKE. If I would have tried to solve it, it probably would have become evident that my equation was wrong. . . . . . .
There, it's set up -- just make a substitution in the line above to solve for q %26amp; d. . .
---------------------------------
3.5r + 2.5c = 43 %26lt;== total cost of (r)oses %26amp; (c)arnations
r + c = 14 %26lt;==== total number of (r)oses %26amp; (c)arnation (in dozens)
Reply:quantity equation
d = q + 6
value equation
10d + 25q = 165
Substitute
10(q + 6) + 25q = 165
10q + 60 + 25q = 165
35q = 105
q = 3
d = q + 6 = 9
9 dimes %26amp; 3 quarters will have a value of
90¢ + 75¢ = $1.65
quantity equation
r + c = 14
r = 14 - c
value equation
3.5r + 2.5c = 43
Substitute
3.5(14 - c) + 2.5c = 43
49 - 3.5c + 2.5c = 43
-c = -6
c = 6
r = 14 - c = 8
8 dozen roses %26amp; 6 dozen carnations will cost
8($3.50) + 6($2.50) = $28.00 + $15.00 = $43.00
Reply:1. let q = quarters and d = dimes
q + 6= d
.25q + .10d = 1.65
Now just use subsitution:
.25q + .10(q + 6) = 1.65
.25q +.10q +.60 = 1.65
.35q = 1.05
q = 3
If there are 3 quarters, then there are 9 dimes.
Check: 3 quarters = .75 and 9 dimes = .90
That adds up to 1.65.
2. Let r = roses and c = carnations
r + c = 14
3.50r + 2.50c = 43
Again, use substitution, or you can add/subtract the two equations, it's up to you. I will use substitution, using the equation r = 14 - c
3.50(14 - c) + 2.50c = 43
49 - 3.50c + 2.50c = 43
-1.00c = -6
c = 6
The florist sold 6 dozen carnations and 8 dozen roses.
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