Answer:
(8,5)
Step-by-step explanation:
5x-2y=30
lets substitute "8" as x and see where that takes us
5(8)-2y=30
40-2y=30
subtract 40 on both sides
-2y=-10
divide by "-2" on both sides
y=5
(8,5) is your answer
Answer:
50%
Step-by-step explanation:
To calculate the percentage of increase, what we must do divide the two quantities, in this way we will be able to know how bigger they are from each other. So:
9000/6000 = 1.5
Now, we subtract those from 1, which would be 100%
1.5 - 1 = 0.5
therefore the increase was 50%
Answer:
She's been charged 84 dollars
Step-by-step explanation:
Let's call each month m
if every month it deducts 7 dollars, then to find how much has been charged after a year, we do
-7 * 12 = -84
Set up a system of equations.
d + q = 75
.1d + .25q = 14.25
Multiply the first equation by -.1 so that the "d's" will cancel.
-.1d -.1q = -7.5
.1d +.25q = 14.25
Now add the two equations together
.15q = 6.75
divide both sides by .15
q = 45
There are 45 quarters in the jar
Answer:
a + b + c + d = 230
Step-by-step explanation:
So first, I am going to write down everything that I can find out from the picture.
a + b = 115
c + d + (180 - a) + (180 - b) = 360
Now, I can use a + b = 115 to simplify c + d + (180 - a) + (180 - b) = 360.
c + d + (360 - (a + b)) = 360
c + d + (360 - 115) = 360
c + d +245 = 360
c + d = 115
Now I know that:
a + b = 115
c + d = 115
Now I can find a + b + c + d
a + b + c + d = (a + b) + (c + d) = 115 + 115 = 230
a + b + c + d = 230
