Answer: a) AB =
; b)
; c) No, they are different; d) No, they are never the same;
Step-by-step explanation:
a) A =
, B =
. This multiplication is possible, because matrix A has 2 columns and matrix B has 2 rows. When those value are equal, the multiplication is possible.
AB =
.
=
b) BA =
.
=
c) As, we can see, parts a and b are differents.
d) With matrices, multiplication is not commutative, which means AB≠BA
Answer:

Step-by-step explanation:
I did this I think 12 years
Answer:
#1
<u>Sum of interior angles is 180:</u>
- y = 180 - (42 + 31) = 107
<u>The law of sines:</u>
- x / sin 107 = 11 / sin 42
- x = 11 sin 107deg / sin 42deg
- x = 15.72
#2
<u>The law of cosines:</u>
- cos 76 = (6² + 17² - x² )/2(6)(17)
- 204*0.24 = 325 - x²
- x² = 325 - 48.96
- x² = 276.04
- x = √276.04
- x = 16.61
#3
<u>Same as above:</u>
- 2*9.4*10*cos 20 = (10² + 9.4² - x²)
- 176.66 = 188.36 - x²
- x² = 188.36 - 176.66
- x² = 11.7
- x = √11.7
- x = 3.42
#4
<u>Sum of interior angles is 180:</u>
<u>The law of sines:</u>
- x / sin 34 = 15 / sin 94
- x = 15 sin 34 / sin 94
- x = 8.41