Respostas

  • Usuário do Brainly
2013-03-08T21:44:29-03:00

é só igualar todos os termos:

 

\left[\begin{array}{cc}2a+1&2b+2\\ab+a&2a+b^{2}\end{array}\right] = \left[\begin{array}{cc}9&-4\\-8&17\end{array}\right]

 

\begin{cases} 2a+1=9\\2b+2=-4\\ab+a=-8\\2a+b^{2}=17\end{cases}

 

2a+1=9 => a=(9-1)/2 => a=4

2b+2=-4 => b=(-4-2)/2 => b=-3

 

ab+a = 4*(-3)+4 = -12+4 = -8 (confere)

2a+b² = 2*4+(-3)² = 8+9 = 17 (confere)