Problem to solve
Solve \[\frac{x+2}{2}+\frac{3y-1}{4}=-1\], \[2x+y-2[3x-4y]=x+3\]
Solution
STEP 1
Solve the following system:
{(x + 2)/2 + 1/4 (3 y - 1) = -1
2 x - 2 (-4 y + 3 x) + y = x + 3
STEP 2
Express the system in standard form:
{(3 y)/4 + x/2 = (-7)/4
9 y - 5 x = 3
STEP 3
Express the system in matrix form:
(1/2 | 3/4
-5 | 9)(x
y) = (-7/4
3)
STEP 4
Solve the system with Cramer's rule:
x = (-7/4 | 3/4
3 | 9)/(1/2 | 3/4
-5 | 9) and y = (1/2 | -7/4
-5 | 3)/(1/2 | 3/4
-5 | 9)
STEP 5
Evaluate the determinant 1/2 | 3/4
-5 | 9 = 33/4:
x = (-7/4 | 3/4
3 | 9)/(33/4) and y = (1/2 | -7/4
-5 | 3)/(33/4)
STEP 6
The gcd of -7/4 | 3/4
3 | 9 and 33/4 is 1/4, so (-7/4 | 3/4
3 | 9)/(33/4) = (4 -7/4 | 3/4
3 | 9)/(4×33/4) = 4/33 -7/4 | 3/4
3 | 9:
x = 4/33 -7/4 | 3/4
3 | 9 and y = (1/2 | -7/4
-5 | 3)/(33/4)
STEP 7
The gcd of 1/2 | -7/4
-5 | 3 and 33/4 is 1/4, so (1/2 | -7/4
-5 | 3)/(33/4) = (4 1/2 | -7/4
-5 | 3)/(4×33/4) = 4/33 1/2 | -7/4
-5 | 3:
x = (4 -7/4 | 3/4
3 | 9)/33 and y = 4/33 1/2 | -7/4
-5 | 3
STEP 8
Evaluate the determinant -7/4 | 3/4
3 | 9 = -18:
x = 4/33×-18 and y = (4 1/2 | -7/4
-5 | 3)/33
STEP 9
4/33 (-18) = (-24)/11:
x = -24/11 and y = (4 1/2 | -7/4
-5 | 3)/33
STEP 10
Evaluate the determinant 1/2 | -7/4
-5 | 3 = (-29)/4:
x = (-24)/11 and y = 4/33×-29/4
STEP 11
4/33×(-29)/4 = (-29)/33:
Answer: | 
 | x = (-24)/11 and y = -29/33