1 gallon for $3 is the better deal because you're getting twice as much for the same price
A Yes as the x values are all different
B f(x) = 5x + 14
when x = 2 , f(x) = 5(2) + 14 = 24
x = 5, f(x) = 39,
Each value of f(x) is greater than corresponding ones in the function in A.
when x = 9 f(x) = 59 which is greater than for first function ( =12)
First function is a decreasing while f(x) is increasing
C f(x) = 64 = 5x + 14
5x = 64 - 14 = 50
x = 10
If you're looking for the solution to the system of equations, here's how we solve using substitution
We know that y = x - 1, so we can plug that into the first equation giving
2x - 3(x-1) = -1
Now distribute the 3 giving 2x - 3x + 3 = -1. After combining like terms we get -x + 3 = -1. Now subtract 3 from both sides, -x = -4, and multiply both sides by -1 to make x positive. x = 4
Now we can plug that into the second equation to get y
y = x - 1, and we know that x = 4, so y = 4 - 1, y = 3. The solution is (4, 3)
