Question

Considerăm E(x) = (2x + 1)² - (x − 1)² + (x − 2)(x + 2) - 3x² + 13. a) Calculați E(-5).​

Answer 1

$\it E(-5)=(-10+1)^2-(-5-1)^2+(-5-2)(-5+2)-3\cdot(-5)^2+13=\\ \\ =(-9)^2-(-6)^2+(-7)(-3)-3\cdot25+13=81-36+21-75+13=\\ \\ =115-111=4$