Question 83793
Y=mX+b IS THE LINE EQUATION WHERE (m)=SLOPE & (b)=Y INTERCEPT.
SUBSTITUTING -3/7 FOR THE SLOPE(m) & THE VALUES FOR X=4 & Y=-7 WE NEED TO SOLVE FOR THE Y INTERCEPT(b).
-7=-3/7*4+b
-7=-12/7+b
b=-7+12/7
b=(-7*7+12)/7
b=(-49+12)/7
b=-37/7 OR -5 2/7 OR -5.2857 ANSWER FOR THE Y INTERCEPT.
PROOF IS THE FOLLOWING GRAPH.
{{{ graph( 300, 200, -15, 5, -10, 10, y = -3x/7 -37/7) }}} (graph 300x200 pixels, x from -15 to 5, y from -10 to 10, y = -3x/7 -37/7).