We can get two different equations from this:
3x = 18
and
3x = -18
So:
x = 6, x = -6
x = {6, -6}
c = cost of food/med for cats
d = cost of food/med for dog
y = total cost/spent
What you know:
y = 6c + d [has 6 cats and 1 dog]
c = 2/3d - 5 [cost for cat is 5 less than 2/3 cost for dog]
y = $195
y = 6c + d
Substitute/plug in what you know, plug in (2/3d - 5) for c and 195 for y
195 = 6(2/3d - 5) + d Distribute/multiply 6 into (2/3d - 5)
195 = 4d - 30 + d Combine like terms
195 = 5d - 30 Add 30 on both sides of the equation
225 = 5d Divide 5 on both sides
$45 = d
Answer:
The diameter of the circle is 9.
Step-by-step explanation:
Because circumference is equal to 
* d, we can backtrack and use this equation to find diameter. Let's say is equal to 3.14.
28.26 = 3.14d
Divide both sides by 3.14.
9 = d
The diameter of the circle is 9.
Lets Anna's age = A
Mr. Goldstein age = G
Mr. Goldstein is 4 times as old as his daughter Anna.
So G= 4A
In 4 years, he will be 3 times as old as Anna
we add 4 with Both their ages
G + 4 = three times of A + 4
G + 4= 3(A + 4)
We know G= 4A, replace it in above equation
4A + 4= 3(A + 4)
4A + 4= 3A + 12
Subtract 3A from both sides
A + 4 = 12
Subtract 4 from both sides
A = 8
So Anna's age = 8 years
