Question

1. Dada a lei de formação B3x4; bij = 2i − 3j, determine:
a) A matriz B,

b) O valor de

b13− b24
b23+ b33

Answer 1

Resposta:

$B=\left[\begin{array}{cccc}b_1_1&b_1_2&b_1_3&b_1_4\\b_2_1&b_2_2&b_2_3&b_2_4\\b_3_1&b_3_2&b_3_3&b_3_4\end{array}\right] \\\\b_i_j=2i-3j\\\\b_1_1=2.1-3.1=2-3=-1\\\\b_1_2=2.1-3.2=2-6=-4\\\\b_1_3=2.1-3.3=2-9=-7\\\\b_1_4=2.1-3.4=2-12=-10\\\\b_2_1=2.2-3.1=4-3=1\\\\b_2_2=2.2-3.2=4-6=-2\\\\b_2_3=2.2-3.3=4-9=-5\\\\b_2_4=2.2-3.4=4-12=-8\\\\b_3_1=2.3-3.1=6-3=3\\\\b_3_2=2.3-3.2=6-6=0\\\\b_3_3=2.3-3.3=6-9=-3\\\\b_3_4=2.3-3.4=6-12=-6$

$a)~~\left[\begin{array}{cccc}-1&-4&-7&7-10\\1&-2&-5&-8\\3&0&-3&-6\end{array}\right]$

b) $b_1_3-b_2_4+b_2_3+b_3_3=-7-(-8)-5-3=-7+8-8=-7$