Answer:
x + y = -2
Step-by-step explanation:
The two primary equations to remember when dealing with graphing 2-variable equations are: ax + by = c (a & b are the x & y coefficients, respectively), and the other is y = mx + c (m = slope, x & y represent themselves). There is another equation to find the slope. If not already known, it's: ∆y/∆x {∆(aka Delta) = difference}. So, since that's all been established, we can proceed to calculate your question:
1) Find your slope: 1 - (-4) = 5 for your y-variable. And -3 - 2 = -5 for your x-variable. So your slope = 5/-5 = -1
2) Use the y = mx + c equation together with either set of (x,y) coordinates to get the equation 1 = (-1)(-3) + c. Which gives you c = -2
3) So, going back to the main equation to remember, the ax + by = c, use a one of your given sets of x,y coordinates and input your known values for x, y, & c to get: a(-3) + b(1) = (-2) and do the same with other set (these are just double-checks, coefficients are all equal to 1 anyways). So, you should arrive to the equation: x + y = -2
As we already have the model that describes the change of the population in Italy in terms of the years that have elapsed, we only have to replace the conditions that are requested in that equation.
Therefore to find the population of Italy in the year 2000 (t = 10 years) substitute t = 10 in the equation and have:

million people
To find the population of Italy in 2008 (t = 18 years)
substitute t = 18 in the equation and have:

million people
To predict the population in Italy for 2015 and 2020 with this model, we substitute in the equation t = 25 and t = 30
t = 25
million people
t = 30
million people
Domain (2 to 4)
Range (-2 to 8)
It’s not a function because there are three points with the x value of 3.
Answer: 13x-1
Step-by-step explanation:
Answer:
Solving a Direct Variation Problem
Write the variation equation: y = kx or k = y/x.
Substitute in for the given values and find the value of k.
Rewrite the variation equation: y = kx with the known value of k.
Substitute the remaining values and find the unknown.
Step-by-step explanation: