One way to solve this problem is to substitute the values of x from the table
and see which function results in the corresponding y-values. The correct
answer, (D), will give an outcome of each y-value when the x-value to its left is
plugged in for x. For example, 3(1) – 4 = 3 – 4 = –1, so the first pair satisfies the
equation. Since 3(3) – 4 = 9 – 4 = 5, the second pair also satisfies the equation,
and so on.
An alternative method would be to input the x- and y-values into two separate
lists on a graphing calculator and perform a linear regression on the data. This
approach may prove to be much less time consuming than trial and error;
however, you need to be both familiar with and comfortable with the method
for finding a linear regression on your particular calculator.
Here is a question in which the calculator is essential.
5. Solve for x: 7 x = 18.52(A) 0.18
(B) 1.5
(C) 2.65
(D) 21.9
(E) 129.64