Question

Qual o valor de m, de modo que -1 seja raiz da equação x³+(m+2)x² +(1-m)x-2=0?

Answer 1

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$x^3+(m+2)x^2+(1-m)x-2=0 \\ \\ f(-1)=(-1)^3+(m+2)(-1)^2+(1-m)(-1)-2 \\ \\ f(-1)=-1+(m+2)(1)-1+m-2 \\ \\ f(-1)=-1+m+2-1+m-2 \\ \\ f(-1)=2m-2 \\ \\ \\ 2m-2=0 \\ \\ 2m=2 \\ \\ m=2\div2 \\ \\ m=1$