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)

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.

y=-2x-7

y=-2x-7