Question

Solutia naturala a ecuatiei 2x pătrat -5x-3=0 este egala cu..

Answer 1

Delta=25+4×2×3=25+24=49
X1=( 5+7)/2×2=12/4=3
X2=( 5-7)/2×2= -2/4= -1/2 care nu e naturala.
Solutia este 3.

Answer 2

$2x^2-5x-3=0 \\ \\ a=2 \\ b=-5 \\ c=-3 \\ \\ \Delta=b^2-4ac \\ \Delta=(-5)^2-4\cdot2\cdot(-3) \\ \Delta=25+24 \\ \Delta=49 \\ \\ \boxed{X_{1,2} = \frac{-b \pm \sqrt{\Delta} }{2a} = \frac{5 \pm 7}{2\cdot2} = } \\ \\ \\ \boxed{X_1= \frac{12}{4}=3 \in N} \\ \\ \\ \boxed{X_2= \frac{-2}{4}= -\frac{1}{2} \in Q}$