Question

2) Encontre o valor de f(x) = x² + 7x - 10 para que f(x) = 0

preciso de ajuda.​

Answer 1

Resposta:

Explicação passo-a-passo:

f(x) = x² + 7x - 10 = 0

$\displaystyle Aplicando~a~f\'{o}rmula~de~Bhaskara~para~x^{2}+7x-10=0~~\\e~comparando~com~(a)x^{2}+(b)x+(c)=0,~temos~a=1{;}~b=7~e~c=-10\\\\\Delta=(b)^{2}-4(a)(c)=(7)^{2}-4(1)(-10)=49-(-40)=89\\\\x^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(7)-\sqrt{89}}{2(1)}=\frac{-7-\sqrt{89}}{2}\\\\x^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(7)+\sqrt{89}}{2(1)}=\frac{-7+\sqrt{89}}{2}\\\\\\S=\{\frac{-7-\sqrt{89}}{2},~\frac{-7+\sqrt{89}}{2}\}$