Question 111979


Find values for m and b in the following system so that the solution to the system is (-3,4)

{{{5x+7y=b}}}

{{{mx+y=22}}}

Since (x,y) = (-3,4), we will have:



{{{5*(-3) + 7*4 = b}}} 

{{{m*(-3) + 4 = 22}}} 
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{{{- 15 + 28 = b}}}…………..=> {{{b = 13}}}

{{{-3m + 4 = 22}}}…………..=> {{{-3m = 22 – 4}}}…….=>{{{-3m = 18}}}….=> {{{m = 18/(-3)}}}…..=> {{{m = -6}}}

Check: 

From the graph we can see that the intersection is ({{{-3}}}, {{{4}}}). 

This means {{{the}}}{{{ solution}}} is ({{{-3}}}, {{{4}}}) which means {{{x=-3}}} and {{{y=4}}}.


*[invoke solve_by_graphing 5, 7, 13, -6, 1, 22]