SAT Mathematics Practice Test 6

linear function has a constant rate of change, and any two rows of the shown table can be used to calculate this rate. From the first row to the second, the value of x is increased by 2 and the value of f(x) is increased by $6=4-\left(-2\right).$So the values of f(x) increase by 3 for every increase by 1 in the value of x. Since $\mathit{f}\left(2\right)=4$, it follows that $\mathit{f}\left(2+1\right)=4+3=7$.Therefore, $\mathit{f}\left(3\right)=7$.Choice A is incorrect. This is the third x-value in the table, not$\mathit{f}\left(3\right)$. Choices C and D are incorrect and may result from errors when calculating the function’s rate of change.