Question

1. Find -5A + 4B
A=[6, 1, -4, -6, 7, -7] B=[-5, -1, -3, -8, 6, 8]

2. Solve the matrix equation.
2X + 2 [2, -8, -4, 2] =[4, -6, 2, -8]

3. Find the product.
[-5,-2,
-8, -5]

[-5, 7,
-9, -5]

4. determine whether the product is defined or undefined. if defined, give the dimensions of the product matrix.
[1, 1, -4, [9, 1, -7]
5, 6, 0]

Answer 1

answer choices.
1. a. [-10, 9, 8, -2, 16, 67]
b. -10, 9, 8, -2, -59, -68] <--------
c. [-50, -9, -1, 16, -11, -68]
d. [-50, -9, 8, -2, -11, 67]

2. a. [0, 5, -3, -2]
b. [0, -11, -3, -6]
c. [0, 5, 5, -6]
d. [4, 5, 5, -2] <------------

3. a. [ 25, 18, -35, 10] <-----------------
b. [43, -25, 85, -31]
c. [40, 45, -56, 25]
d. [43, -25, -31, 85]

4. a. defined; 3 x 3
b. defined; 2 x 1
c. defined; 2 x 3 <------------
d. undefined

Answer 2

hallp ;-;

Answer 3

@jim_thompson5910 can you help? please ;-;

Answer 4

if A=[6, 1, -4, -6, 7, -7], then what is -5A ?

Answer 5

I forgot what i need to do..

Answer 6

-5A tells you to multiply everything in matrix A by -5

Answer 7

OH RIGHT. Okay. That means I multiply everything in b by 4. What about the rest?

Answer 8

once you find -5A and 4B, you add up the matrices

Answer 9

you add by adding up the corresponding components

Answer 10

thanks! it's d.

what about number 2-4?

Answer 11

first compute 2 [2, -8, -4, 2]

Answer 12

okay

Answer 13

[4, -16, -8, 4]

Answer 14

so

2X + 2 [2, -8, -4, 2] =[4, -6, 2, -8]

is the same as

2X + [4, -16, -8, 4] =[4, -6, 2, -8]

Answer 15

then you subtract [4, -16, -8, 4] from both sides to isolate 2X

the ultimate goal is to completely isolate X

Answer 16

right so, [0, -10, 2, -12]

Answer 17

2X + [4, -16, -8, 4] =[4, -6, 2, -8]

2X =[4, -6, 2, -8] - [4, -16, -8, 4]

2X =[4-4, -6-(-16), 2-(-8), -8-4]

2X =[4-4, -6+16, 2+8, -8-4]

2X =[0, 10, 10, -12]

X = ??

Answer 18

[0, 5, 5, -6] right? So it's C.

Answer 19

good

Answer 20

thank you :D

What about number 3 and 4?

Answer 21

so despite that slight error, it looks like you got a handle on it

Answer 22

The problem is



right?