tolong di bantu kk buat hari ini kalo di jawab aku beliin pulsa

A×X  = B 

2   2       a   b            2a + 2c      2b + 2d  
3   4   ×  c   d     =     3a + 4c     3a  + 4d  


2a + 2c = 8 (dikali 2) 
3a + 4c = 15 

4a + 4c = 16 
3a + 4c = 15
__________ - 
⇒⇒ a = 1 
⇒2a + 2c = 8 
2(1) + 2c = 8 
2c = 6 
⇒⇒c = 3 


2b + 2d = 12 (dikali 2)
3b + 4d = 22

4b + 4d = 24 
3b + 4d = 22 
____________- 
b = 2 

⇒2b + 2d = 12 
2(2) + 2d = 12 
4 + 2d = 12 
2d = 8 
d = 4 

jawabannya= E 

a    b   ⇒⇒    1     2 
c    d               3     4

15

X = A⁻¹ B

[tex] x\,= \frac{1}{2} \left[\begin{array}{ccc}4&-2\\-3&2\end{array}\right] \left[\begin{array}{ccc}8&12\\15&22\end{array}\right]\,= \left[\begin{array}{ccc}1&2\\3&4\end{array}\right] [/tex]


16.
g = b-a
h = d-c

g (1, -4, 1)
h (1 ,-4, -1)

g.h = 1 +16  -1 = 16
|g| = √(1+16+1) = √18
|h| = √(1+16+1) = √18

cos α  = ( g . h)/ |g||h|
cos α  =  16/ 18= 8/9
sin α = √(1 - cos² α) = √( 1- 64/81) = √(17/81)
sin α = (√17 ) / 9