`3x+4y>=12`, `4x+7y<=28`, `y>=1`, `x>=0`,`y>=0`.

Find the orthocentre of the triangle formed by 4x-7y+10=0, x+y-5=0, 7x+4y-15=0 .

The area of the quadrilateral formed by thelines 4x-7y-13=0, 8x-y-39=0, 4x-7y+39=0, 8x-y+13=0 is

3x-4y=-7,5x-2y=0

Classify the following pairs of lines as coincident, parallel, perpendicular or intersecting : (i) 6x+14y-16=0 , 12x+28y-32=0 (ii) 3x-4y=8 , 3x+4y=11 (iii) 5x-2y=7 , 2y-5x=-7 (iv) 4x+7y=19 , 7x-4y=-2 (v) x-2y=7 , 4y-2x=13

Given the four lines with the equations x+2y-3=0 , 3x+4y-7=0 , 2x+3y-4=0 , 4x+5y-6=0 , then

Given the four lines with the equations x+2y-3=0 , 3x+4y-7=0 , 2x+3y-4=0 , 4x+5y-6=0 , then

Solve the following graphically x + 4y le 8 , 3x - 4y le 12 , x ge 0 , y ge 0

Find the equation of the bisectors of the internal angles of the triangle whose sides are : 3x+4y-6=0 , 12x-5y-3=0 , 4x-3y+12=0

Z= 4x + 7y x + 2y le 20, x + y le 15, x ge 0, y ge 0 .