Answer:
x = -2 and y = 3
{y = -3 x - 3, y = (3 x)/4 + 9/2} = x = -2 and y = 3
Step-by-step explanation:
Solve the following system:
{6 x + 2 y = -6
3 x - 4 y = -18
Express the system in matrix form:
(6 | 2
3 | -4)(x
y) = (-6
-18)
Solve the system with Cramer's rule:
x = -6 | 2
-18 | -4/6 | 2
3 | -4 and y = 6 | -6
3 | -18/6 | 2
3 | -4
Evaluate the determinant 6 | 2
3 | -4 = -30:
x = -6 | 2
-18 | -4/(-30) and y = 6 | -6
3 | -18/(-30)
Simplify -6 | 2
-18 | -4/(-30):
x = -1/30 -6 | 2
-18 | -4 and y = 6 | -6
3 | -18/(-30)
Simplify 6 | -6
3 | -18/(-30):
x = -(-6 | 2
-18 | -4)/30 and y = -1/30 6 | -6
3 | -18
Evaluate the determinant -6 | 2
-18 | -4 = 60:
x = (-1)/30×60 and y = -(6 | -6
3 | -18)/30
(-1)/30×60 = -2:
x = -2 and y = -(6 | -6
3 | -18)/30
Evaluate the determinant 6 | -6
3 | -18 = -90:
x = -2 and y = (-1)/30×-90
(-1)/30 (-90) = 3:
Answer: x = -2 and y = 3
___________________________________________
Solve the following system:
{y = -3 x - 3
y = (3 x)/4 + 9/2
Express the system in standard form:
{3 x + y = -3
-(3 x)/4 + y = 9/2
Express the system in matrix form:
(3 | 1
-3/4 | 1)(x
y) = (-3
9/2)
Write the system in augmented matrix form and use Gaussian elimination:
(3 | 1 | -3
-3/4 | 1 | 9/2)
Add 1/4 × (row 1) to row 2:
(3 | 1 | -3
0 | 5/4 | 15/4)
Multiply row 2 by 4/5:
(3 | 1 | -3
0 | 1 | 3)
Subtract row 2 from row 1:
(3 | 0 | -6
0 | 1 | 3)
Divide row 1 by 3:
(1 | 0 | -2
0 | 1 | 3)
Collect results:
Answer: {x = -2
, y = 3
