Question

pls urgent!!!!
Q.1an edge of the cube is increased by 10%. Find the % by which the surface area of the cube has increased.
Q.2if (2,3) lies on 2x-3y-5k=0. Write another. two solutions of the equation.

Answer 1

Surface area of cube = A = 6 a²
So  ΔA/A * 100 = 2 * Δa/a * 100
                         = 2 * 10  = 20%

=====
    2x - 3 y - 5 k = 0
   (x,y) = (2,3) lies on the straight line.
   So  2*2 - 3*3 - 5 * k = 0     =>  k = -1
   So: equation of the line is  2 x - 3 y + 5 = 0
   Let x = -1,  y = 1.
         x = 0,   y = 5/3
         y = 0,  x = 2.5

Hence (-1, 1),  (0, 5/3),  (2.5, 0) are three more solutions