Answer:
Hello there are only 2 real solutions where x_1 = 11, x_2 = 7, x_3 = 3 and x_1 = 4, x_2 = 7, x_3 = 10
Step-by-step explanation:
Lets begin with arithmetic progression we know that we need some d which we will add to our x_1 to get x_2, so let's write it : x + (x+d) +(x+2d) = 21 and x*(x+d)*(x+2d) = 231 and that should be it.
