Question

9) Determine a soma dos elementos da matriz linha (1×5)que obedece a lei :2i2-7j

Answer 1

M[  a11,a12,a13,a14,a15]    1x5    lei  2i2-7j= 4i-7j

A11= 4.1-7.1⇒4-7=-3
A12=4.1-7.2⇒4-14= -10
A13=4.1-7.3⇒4-21=-17
A14= 4.1-7.4⇒⇒4-28=-24
A15=4.1-7.5⇒4-35= -31
[ -3  -10 -14  -24 -31]

soma dos 5 elementos= -85

Answer 2

$A=(a_{ij})_{1\times5}\qquad\qquad\qquad{a}_{ij}=2i^2-7j\\\\\\A=\left[\begin{array}{aaaaa}a_{11}&a_{12}&a_{13}&a_{14}&a_{15}\end{array}\right]\\\\\\a_{11}=2(1)^2-7(1)\longrightarrow{a}_{11}=2(1)-7\longrightarrow{a}_{11}=2-7\longrightarrow{a}_{11}=-5\\\\a_{12}=2(1)^2-7(2)\longrightarrow{a}_{12}=2(1)-14\longrightarrow{a}_{12}=2-14\longrightarrow{a}_{12}=-12\\\\a_{11}=2(1)^2-7(3)\longrightarrow{a}_{11}=2(1)-21\longrightarrow{a}_{11}=2-21\longrightarrow{a}_{11}=-19\\\\a_{14}=2(1)^2-7(4)\longrightarrow{a}_{14}=2(1)-28\longrightarrow{a}_{14}=2-28\longrightarrow{a}_{14}=-26\\\\a_{15}=2(1)^2-7(5)\longrightarrow{a}_{15}=2(1)-35\longrightarrow{a}_{15}=2-35\longrightarrow{a}_{15}=-33\\\\\\\\a_{11}+a_{12}+a_{13}+a_{14}+a_{15}=\ ?\\\\(-5)+(-12)+(-19)+(-26)+(-33)\Longrightarrow-5-12-19-26-33=\boxed{\boxed{-95}}$