Which one is linear 2X+3y=4 2+y2= 7-X2+X 3 =6 z=5-3X+y/2 sinⅹ+ey=1 =2 7X1+3X2+9/X2+2X4=1 X1+2X2+3x3+…+nXn=14 2x + 3y = 4 x 2 + y 2 = 1 x1 - x2 + x3 - x4 = 6 z = 5 - 3x + y/2 sin x + e y = 1 xy = 2 7x1 + 3x2 + 9/x3 + 2x4 = 1 x1 + 2x2 + 3x3 +....+ nxn = 1 Which one is linear?