Question

calcule o valor de 3x^4-2x+4x^-1,para x=10^-1.de a resposta na forma decimal.

Answer 1

$3 {x }^{4} - 2 x + 4{x}^{ - 1} = y\\ 3( { {10}^{ - 1} )}^{4} + 2 \times {10}^{ - 1} + 4( { {10}^{ - 1} )}^{ - 1} = y\\ 3 \times {10}^{ - 4} + 2 \times {10}^{ - 1} + 4 \times 10 = y\\ 3 \times \frac{1}{ 10000} + 2 \times \frac{1}{10} + 40 = y \\ \frac{3 \times 1 + 2 \times 1 \times 1000 + 40 \times 10000}{10000} = y\\ y = \frac{402003}{10000} \\ y = 40.2003$