Question

Calcule o valor da expressão algébrica e=x² +3x-5 para:

A) x=2 B) x= 0,5 C) x= -1 D) x= -0,1

Answer 1

$x^{2} +3x-5\\\\\\\\ A)~~Para\to~~x=2:\\\\ 2^{2} +3.2-5\to~~4+6-5\to~~10-5\to~~\large\boxed{5}\\\\\\\\ B)~~Para\to~~x=0,5:\\\\ 0,5^{2} +3.0,5-5\to~~0,25+1,5-5\to~~1,75-5\to~~\large\boxed{-3,25}\\\\\\\\ C)~~Para\to~~x=-1:\\\\ (-1)^{2} +3.(-1)-5\to~~1+3-5\to~~4-5\to~~\large\boxed{-1}\\\\\\\\ D)~~Para\to~~x=-0,1:\\\\ (-0,1)^{2} +3.(-0,1)-5\to~~0,01-0,3-5\to~0,01-5,3\to~ \large\boxed{-5,29}$