Answer:
Could you Write the question more clearly?
Step-by-step explanation:
Answer:
36-54i
Step-by-step explanation:
(9+9i)(-1-5i)
v
-9-9×5i-9i-9i×5i
v
-9-45i-9i-45i^2
v
-9-45i-9i-45×(-1)
v
(-9)-45i-9i+(45)
v
36(-45i)(-9i)
v
36-54i
If you have multiple equations with multiple variables, you can either do clever substitutions, or turn it into a matrix on which you can perform linear combinations or multiplications (Gauss elimination)
1 1 1 1
2 1 -1 8
1 -1 1 -5
(note how the above 3 rows represent the 3 equations, just got rid of the variables, plus sign and equals sign)
subtract row1 from row3, that eliminates x and z from row 3.
1 1 1 1
2 1 -1 8
0 -2 0 -6
divide row3 by -2, that will give y a factor of 1
1 1 1 1
2 1 -1 8
0 1 0 3
The last row now says y=3
