Question

Qual o valor numérico da expressão a ³-2a² +5a, para a= 2/3

Answer 1

a ³-2a² +5a
(2/3)^3 - 2(2/3)^2 + 5(2/3)
(8/27) - 2(4/9) + (10/3)
(8/27) - (8/9) + (10/3)
(8 - 24 + 90) / 27
(98 - 24) / 27
74 / 27