Set the two values equal to each other with 18x-2=12x+2 and then plug it in to the equation and solve
Answer:
The constant of variation is 3
Step-by-step explanation:
Given.


And y is directly related to x
∝ 
Here k is constant of variation

--------------(1)
Put the
and
value in equation 1.


So, the constant of variation is 3.
D=number of dimes
q=number of quarters
let's count everything in cents
dimes are worth 10 cents
quarters are worth 25 cents
10d+25q=700
divide both sides by 5
2d+5q=140
he has 7 more quarters than dimes
q=7+d
subsitute 7+d for q in other equation
2d+5q=140
2d+5(7+d)=140
2d+35+5d=140
7d+35=140
minus 35 both sides
7d=105
divide both sides by 7
d=15
sub back
q=7+d
q=7+15
q=22
22 quarters and 15 dimes
The ratio is 9:81 which is equivalent to 1:9