Answer:
y = 6
Step-by-step explanation:
If x varies inversely proportional as y.
, k is constant of proportionality
or
k = xy
When x = 3 and y = 10
k = 3×10
k = 30
Put x = 5,

So, the value of y is 6 when x is 5.
The sum of two numbers:
x + y = 108
The difference of the same two numbers:
x - y = 78
We can use substitution to figure out x and y:
x - y = 78 can be changed to x = 78 + y
We can plug this into the first equation:
78 + y + y = 108
78 + 2y = 108
2y = 30
y = 15
Now solve for x using any of the two equations. I'll use the first equation since it's easier:
x + 15 = 108
x = 93
Callum must buy one packet of dog food every 10 days
Answer:
Step-by-step explanation:
Not QUITE a parabola . but up until y = 4 it is close
Vertex = (-7-10)
Vertex form of parabola
y = a ( x+7)^2 -10 find a integer-coordinat point to calculate 'a'
I'll use -18,0
0 = a(-18+7)^2 -10
0 = 122 a -10 a = 10/122
y = 10/122 (x+7)^2 - 10 see graph below: