Given the equation:
[tex]y=mx+b,[/tex]if you substitute the given data, you get the following system of equations:
[tex]\begin{gathered} 7760=240m+b, \\ 11750=450m+b. \end{gathered}[/tex]Subtracting the first equation from the second one, you get:
[tex]11750-7760=450m-240m+b-b.[/tex]Simplifying you get:
[tex]3990=210m.[/tex]Solving for m, you get:
[tex]m=\frac{3990}{210}=19.[/tex]Substituting m=3990 in the first equation, and solving for b you get:
[tex]\begin{gathered} 7760=19(240)+b, \\ b=7760-19(240), \\ b=3200. \end{gathered}[/tex]