Answer:
Complete the square on x by adding <u>49</u> to both sides.
Complete the square on y by adding <u>81</u> to both sides.
Step-by-step explanation:
We have been given an equation 
. We are asked to complete the squares for both x and y.
We know to complete a square, we add the half the square of coefficient of x or y term.
Upon looking at our given equation, we can see that coefficient of x is 14 and coefficient of y is 18.
Now, we will add 49 to complete the x term square and 81 to complete y term square on both sides of our given equation as:
Applying the perfect square formula 
, we will get:
Therefore, We can complete the square on x by adding <u>49</u> to both sides and the square on y by adding <u>81</u> to both sides.
Well if you're wanting to use substitution, you first have to end up with one term on either side of the equation. Use the second one as it's easiest.
So: x-2y=11, so find -2y as there is a -2y in the first equation.
then that becomes -2y=11-x. then sub that into equation 1, and you get:
-x+11-x=-13, which equals to -2x+11=-13, which is -2x=-24, so therefore
x=12. then chuck the x into any of the equations to find what y equals.
hope this helps!
5x - 2y + 1z = 8 ⇒ 5x - 2y + 1z = 8
-9x + 2y + 2z = 5 ⇒ -9x + 2y + 2z = 5
-9x - 2y - 5z = 4 -4x + 3z = 13
5x - 2y + 1z = 8
-9x + 2y + 2z = 5 ⇒ -9x + 2y + 2z = 5
-9z - 2y - 5z = 4 ⇒ -9x - 2y - 5z = 4
-18x - 3z = 9
-4x + 3z = 13
-18x - 3z = 9
-22x = 22
-22 -22
x = -1
-18x - 3z = 9
-18(-1) - 3z = 9
18 - 3z = 9
- 18 - 18
-3z = -9
-3 -3
z = 3
5x - 2y + z = 8
5(-1) - 2y + 3 = 8
-5 - 2y + 3 = 8
-2y - 5 + 3 = 8
-2y - 2 = 8
+ 2 + 2
-2y = 10
-2 -2
y = -5
(x, y, z) = (-1, -5, 3)
