05(2q)+.25q2.8=.1q+.25q2.8=.......
n =2q
And they equal $2.80 so:
2.8=.05n+.25q
And input:
2.8=.05(2q)+.25q
2.8=.1q+.25q
2.8=.35q
q=8
4) There are 6 more quarters than nickels.
n+6=q
5.70=.05n+.25q
Input the first equation into the second:
5.70=.05n +.25(n+6)
5.70=.05n+.25n+1.5
5.70=.30n+1.5
4.20=.30n
n=14
5) 63 visors were bought and plain and logo visors were sold so:
63=p+l
A total of 350 was earned so:
360=5p+6l
Re-arrange the first equation to solve for p.
l=63-p
Input into second equation:
360=5p+6(63-p)
360=5p+378-6p
360=-p+378
-18=-p
p=18
6) 25 fruit were sold all together so:
25=p+o
They earned $6.00 from the oranges and peaches combined.
6.00=.20p+.30o
Re-arrange to solve for peaches:
o=25-p
6.00=.20p+.30(25-p)
6.00=.20p+7.5-.30p
6.00=(-.1)p+7.5
-1.5=(-.1)p
p=15
Too many questions. I'll try to explain though.
Basically in 1, there are 36 dimes and quarters. Let x represent the number of dimes. Therefore, 36-x=the number of quarters.
To find the number of dimes for 1, what you do is solve for .10(value)(x)(this is the total value of the dimes)+.25(value(36-x)(this is the total value of the quarters)=4.80. So, .10x+.25(36-x)=4.80. Just solve for x, which represents the number of dimes and you'll get your answer. If you need the cost, just switch the roles(which is variable and which isn't).
You are much better off asking these individually. Not many people are going to want to sit here and answer 6 questions, all basically on the same subject.
Here's the first one.
-.10(x + y = 36)
-.10x - .10y = -3.60
.10x + .25y = 4.80
---------------------------
.15y = 1.20
y = 1.20 / .15
y = 8
y was the quarters and we wanted x.
x + y = 36
x + 8 = 36
x = 28
28 Dimes.
