IBA maths qs..help

[Gordious]

A triangle is formed by the x-axis, y-axis, and the line y = ax + b. If a = -b, then what is the volume of the cone generated by rotating this triangle around y-axis?

if the perimeter of rectangle is 60 meters and its area is 200 square m, then one of its sides must be___________the other sidea)
A)1/3 B)triple C)Double D)1/10

 

[Gordious]

Inorder that the system of equations ax+2y=b,3x-y=c has no solution
a is not = to 6
a is not = to -6
a is not = b
b is not = c ??