line 1: 3y+4x=-6...strate line: y=-(4/3)x -2
line 2: 4y-3x=12...strate line y=+(3/4)x+3
line 1 slope=-4/3
line 2 slope=+3/4...this =-1/slope av line1...that meen 2 lines 90 deg apart
tu see if 2 lines hit, put y from line 1 intu line 2
4*[-(4/3)x -2] -3x=12
-(16/3)x -3x=12 +8
-(25/3)x=20
x=-(3/25)*20
x=-2.4
y=-(4/3)x -2=(4/3)*(2.4) -2 =3.2-2
y=1.2
2 lines hit at (-2.4,+1.2)