If the lines y=2x+3,  y=3x+4 and y=mx+7  are concurrent then  m=

Three lines are said to be concurrent, if those three lines are passing through the same point. To get the point of intersection of two lines y=2x+3,  y=3x+4Equate both equations 2x+3=3x+4x=−1Substitute x=-1 , in the equation y=3x+4  y=3−1+4=1The point of intersection is  −1,1Since three lines are concurrent, the point −1,1 lies on the line  y=mx+7Hence, 1=−m+7m=6Therefore,m=6