Question

a system of liner equations includes the line that is created by the equation y=x+3, graphed below and the line through the points (3,1) and (4,3). A.(-1,2) B.(1,3) C.(8,11) D.(9,12)

Answer 1

m=(y2-y1)/(x2-x1)= (3-1)/(4-3) =(2/1)= 2
y=mx+b. plug in one of the points for the second line and solve for b
1=2(3)+b
1=6+b
-5=b
plug b and m back into the equation y=mx+b
y=2x+-5
The solution to the system must make sense when plugged into both equations
C works because
y=x+3; 11=8+3
11=11 and
y=2x-5; 11=2(8)-5
11=11