Question

the sum of three no in A.P is 12 and the sum of their cubes is 288. Find the nos

Answer 1

a1=a, a2= a+(n-1)d= a+d, and a3=a+2d similarly
a+a+d+a+2d=12
3a+3d=12
a+d+12/3=4
a2=a+d=4
(a)^3+64+(a+2d)^3=288                       (a+b)^3=a^3+3a^2b+3ab^2+b^3. 
2a^3+64+6a^2d+8d^3+24ad^2=288
so you now have 2 equations. Use them to solve the rest