`6^x+6^y=42 , x+y=3`

Solve: 6x - 3y = 13, 2x + y =3

4x-3y=8, 6x-y=29/3

2x + y = 6, 6x + 3y = 18 .

Prove that the following lines are concurrent. (i)5x-3y=1 , 2x+3y=23 , 42x+21y=257 (ii) 2x+3y-4=0 , x-5y+7=0 , 6x-17y+24=0

2x - 3y = 12, x + 3y = 6 .

Find y' , y'' and y''' if y= x^3 - 6x^2 - 5x +3.

4x-2y=3 6x-3y=5

(6) 2x-3y=4 ; 3y-x=4