Question

ma ajudem pfvr!!! dou 15 pontos

Answer 1

1. Seja a matriz A = $\left[\begin{array}{cc} a_{11} &a_{12}\\a_{21}&a_{22}\\\end{array}\right]$

Vamos determinar cada elemento $a_{ij}$ através da lei:

$a_{ij} = i^{2} - 3j + ij$

$a_{11} = (1)^{2}-3(1) + (1)(1)= 1 - 3 + 1 = -1 \\ a_{12} = (1)^{2}-3(2) + (1)(2) =1 - 6 + 2 = -3\\ a_{21} =(2)^{2}-3(1) + (2)(1) = 4-3+2=3\\ a_{22} = (2)^{2}-3(2) + (2)(2) = 4-6+4=2$

Então: A = $\left[\begin{array}{cc} -1 &-3\\3&2\\\end{array}\right]$

2.
$\left[\begin{array}{cc} 3x+10 &0\\0&4y-9\\\end{array}\right] = \left[\begin{array}{cc} 1 &0\\0&1\\\end{array}\right] \\ \\ \left \{ {{3x+10=1} \atop {4y-9=1}} \right.$


3x+10 = 1
3x = 1-10
3x = -9
x = -9/3
x = -3

4y-9 = 1
4y = 1+9
4y = 10
y = 10/4
y= 5/2