find the slope of the tangent line to the graph of f at the given point. Graph f and the tangen line.

9. f(x) = 3x +5 at (1.8)

10. f(x)=2x + 1 at (-1,3)

Please, help me with this problems.
thanks

Are you also posting under the name of Mara ?

see http://www.jiskha.com/display.cgi?id=1318997362