Answer:
(5,15)
Step-by-step explanation:
We know that 225 = 15a + 10c, and he purchased a total of 20 tickets, so
a + c = 20, using this, we know that c = 20 - a, we can substitute this for c in 225 = 15a + 10c to get:
225 = 15a + 10(20 - a) =
225 = 15a + 200 - 10a
225 = 5a + 200
25 = 5a
a = 5
Now we substitute 5 for a:
225 = 15a + 10c
225 = 15(5) + 10c
225 = 75 + 10c
150 = 10c
c = 15
so a = 5 and c = 15, the solution is (5,15)
P.S. I'm the guy who did your other question
Let g = graph paper and r = ruler
1st equation: 5g + 30r = 40
2nd equation: 12g + 20r = 44
Multiply the 2nd equation by -1.5 to cancel out the r's
2nd equation: 12g + 20r = 44 x -1.5 = -18g - 30r = -66
Now add the 1st equation to that:
-18g + 5g = -13g
30r -30r = 0
40 -66 = -26
The new equation becomes -13g = -26
Divide both sides by -13
g = -26 / -13
g = 2
This means each pack of graph paper cost $2.
Now replace g with 2 in the first equation to solve for the cost of a rule:
5(2) + 30r = 40
Simplify:
10 + 30r = 40
Subtract 10 from each side:
30r = 30
Divide both sides by 30:
r = 30 / 30
r = 1
Each rule cost $1.
Answer:
Ez
Step-by-step explanation:
Change each number to an improper fraction.
Simplify if possible.
Multiply the numerators and then the denominators.
Put answer in lowest terms.
Check to be sure the answer makes sense.
Step-by-step explanation:
6r + 7 = 13 + 7r
6r - 7r = 13 - 7
-1r = 6
r = 6/-1
r = -6
