Question

Make up an equation of the form y = kx +b, the graph of which passes through the following points: C (–19, 31) and D (1, –9)

Answer 1

Try this way:
it is possible to make up the system of two equations using the coordinates of points C and D:
31=k*(-19)+b - if to substitute the coordinates of point C;
-9=k*1+b - if to substitute the coordinates of point D.

`\left \{ {{-19k+b=31} \atop {k+b=-9}} \right. \ =\ \textgreater \ \ \left \{ {{20k=-40} \atop {k+b=-9}} \right. \ =\ \textgreater \ \ \left \{ {{k=-2} \atop {b=-7}} \right.`
y=-2x-7

answer: y=-2x-7