(a(3 + a))/(3) \leqslant \frac{z(a - 1) {}^(2) }{15} - ((a - 1)(4 - a))/(5) + (1)/(5) can anyone help me?​

Question

`(a(3 + a))/(3) \leqslant \frac{z(a - 1) {}^(2) }{15} - ((a - 1)(4 - a))/(5) + (1)/(5)`

can anyone help me?​

Answer 1

a= 15+z+ square root 17(z+15)/ z-2
z=2a^2/(a-1)^2 + 30a/(a-1)^2 - 15/(a-1)^2