Answer:
x+y=28
70x+140y=3360
8 cats, 20 dogs were sold
Step-by-step explanation:
Let x=cats y=dogs
We know that a total of 28 pets were sold which means that
x+y=28
We also know that they made 3360 which means that
70x+140y=3360
It doesn't really say if you need to solve this but I will anyways
We use the first equation (x+y=28) and subtract 28 and y from both sides to get
x-28= -y we can then divide both sides by -1 so y can be a positive
-x+28=y
This is what y equals in terms of x and so we can plug this in for y in the second equation
70x+140(-x+28)=3360
Distribute the 140 and get
70x-140x+3920=3360
Add like terms and subtract 3920 to get
-70x=-560
divide both sides by -70 and get
x=8
We now know that 8 cats were sold and can plug this value into any equation to solve for y ( I will be using the first one because that's easiest)
8+y=28
subtract 8 and get
y=20
