Question

4) qual deve ser o valor de p na equação 10X²-px-1=0 para que a soma de suas raízes seja igual 3\4.

Answer 1

Olá !

Resolução :

$\mathsf{ S =\dfrac{-b}{a}} \\\\\\ \mathsf{\dfrac{3}{4} =\dfrac{-(-p)}{10}} \\\\\\ \mathsf{\dfrac{3}{4} =\dfrac{p}{10}} \\\\\\ \mathsf{4p = 10\cdot3} \\\\\\ \mathsf{ 4p = 30} \\\\\\ \mathsf{ p =\dfrac{30}{4}} \\\\\\ \mathsf{ p =\dfrac{15}{12}}$

Resposta :

$\mathsf{p =\dfrac{15}{2}}$