Answer:
For the first question
and
For the second question 
Step-by-step explanation:
Given:
1.
x - 3y = 7
3x + 3y = 9
2.
8x+ 3y = 1
4x + 2y = 0
Elimination method :
In the elimination method we need to make the coefficient of x or the coefficient of y same in both the equation so by adding or subtracting we can eliminate the x term or the y term.
Then substitute that values which you will get on eliminating in any equation you will get the corresponding value.
For the first question, the y coefficient is same hence by adding both the equation we can eliminate 3y term. so on solving we get

Now substitute X equal to 4 in equation x -3y = 7 we get

This way we have x is equal to 4 and y is equal to -1 for question number 1.
For the second question, we will make X coefficient same in the second equation that is multiplying by 2 to the equation 4x + 2y = 0 then we get

Now the coefficient of x term become same now we will subtract the two equations that is 8x + 3y = 1 and 8x + 4y =0 we get

Now substitute y equal to -1 in equation 8x +3y = 1 we get

This way we have x is equal to 0.5 and y is equal to -1 for question number 2.
Answer:
The complex number
has Cartesian form
.
Step-by-step explanation:
First, we need to recall the definition of
when
is a complex number:
.
Then,
. (I)
Now, recall the definition of the complex exponential:
.
So,

(we use that
.
Thus,

Now we group conveniently in the above expression:
.
Now, substituting this equality in (I) we get
.
Thus,

.
3x+2=x+2x+4
-2 -2
3x=x+2x+4-2
3x=3x+4-2
-3x -3x
x= 4-2
x=2
Answer:
x = -1.3
Step-by-step explanation:
5x +9=2.5
subtract 9 from both sides
5x = -6.6
divide both sides by 5
x=-1.3
In not sure about the
+4 (29+1)
part
and if there was supposed to be a "q" in there but this is the answer