4x-5y +7z= -14
9x + 2y +3z= 47
-y + x -5z = 11

Find x if A'B​

x = 5

Step-by-step explanation:

Here we have the system of equations:

4x - 5y +7z= -14

9x + 2y +3z= 47

-y + x -5z = 11

We want to find the value of x.

To do it, we need to isolate one variable (not x) in one of the 3 equations. We could isolate y in the third equation to get:

x - 5z - 11  = y

now we can replace this in the other two equations to get:

4x - 5*( x - 5z - 11 ) +7z = -14

9x + 2*(x - 5z - 11 ) + 3z = 47

notice that now we have only two variables, now we need to simplify these two equations so we can get:

-x + 32z  = -69

11x - 7z  = 69

Now we do the same thing, this time we need to isolate z in one of the two equations, let's isolate it in the second one:

7z = 11x - 69

z = (11/7)*x - (69/7)

now we can replace this in the other equation to get:

-x + 32*( (11/7)*x - (69/7) ) = -69

now we have an equation for x, that we can solve to find its value:

-x + 32*(11/7)*x - 32*(69/7) = -69

x*(32*(11/7) - 1) = -69 + 32*(69/7)

x = [-69 + 32*(69/7)]/(32*(11/7) - 1) = 5

The value of x is 5.

4

step-by-step explanation:

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i