The slope-intercept form: \(y= mx + b\)
The slope-point form: \(y-y_1=m(x-x_1)\)
The slope: \(m=\dfrac{y_2-y_1}{x_2-x_1}\)
\((3; 6)\to x_1=3;\ y_1=6\\(5;\ 18)\to x_2=5;\ y_2=18\)
subtitute
\(m=\dfrac{18-6}{5-3}=\dfrac{12}{2}=6\)
\(y-6=6(x-3)\\\\y-6=6x-18\ \ \ \ |add\ 6\ to\ both\ sides\\\\y=6x-12\)
Answer: b. f(x)=6x - 12
