Problem to solve
Solve \[\frac{2x+y}{3}-\frac{2[x+y]}{4}=2\], \[-\frac{2[x-y]}{5}-\frac{x+2y}{2}=-1\]
Solution
STEP 1
Solve the following system:
{1/2 (-y - x) + 1/3 (y + 2 x) = 2
1/2 (-2 y - x) - 2/5 (-y + x) = -1
STEP 2
Hint: | Expand the left hand side of the equation 1/2 (-y - x) + 1/3 (y + 2 x) = 2.
(-y - x)/2 + (y + 2 x)/3 = (-y/2 - x/2) + (y/3 + (2 x)/3) = -y/6 + x/6:
{(-y/6 + x/6) = 2
1/2 (-2 y - x) - 2/5 (-y + x) = -1
STEP 3
Hint: | Expand the left hand side of the equation 1/2 (-2 y - x) - 2/5 (-y + x) = -1.
(-2 y - x)/2 - (2 (-y + x))/5 = (-y - x/2) + ((2 y)/5 - (2 x)/5) = -(3 y)/5 - (9 x)/10:
{-y/6 + x/6 = 2
(-(3 y)/5 - (9 x)/10) = -1
STEP 4
Hint: | Choose an equation and a variable to solve for.
In the first equation, look to solve for x:
{-y/6 + x/6 = 2
-(3 y)/5 - (9 x)/10 = -1
STEP 5
Hint: | Isolate terms with x to the left hand side.
Add y/6 to both sides:
{x/6 = (y + 12)/6
-(3 y)/5 - (9 x)/10 = -1
STEP 6
Hint: | Solve for x.
Multiply both sides by 6:
{x = y + 12
-(3 y)/5 - (9 x)/10 = -1
STEP 7
Hint: | Perform a substitution.
Substitute x = y + 12 into the second equation:
{x = y + 12
-(3 y)/5 - (9 (y + 12))/10 = -1
STEP 8
Hint: | Expand the left hand side of the equation -(3 y)/5 - (9 (y + 12))/10 = -1.
(-3 y)/5 - (9 (y + 12))/10 = -(3 y)/5 + (-(9 y)/10 - 54/5) = -(3 y)/2 - 54/5:
{x = y + 12
(-(3 y)/2 - 54/5) = -1
STEP 9
Hint: | Choose an equation and a variable to solve for.
In the second equation, look to solve for y:
{x = y + 12
-(3 y)/2 - 54/5 = -1
STEP 10
Hint: | Isolate terms with y to the left hand side.
Add 54/5 to both sides:
{x = y + 12
-(3 y)/2 = 49/5
STEP 11
Hint: | Solve for y.
Multiply both sides by -2/3:
{x = y + 12
y = -98/15
STEP 12
Hint: | Perform a back substitution.
Substitute y = -98/15 into the first equation:
Answer: | 
 | {x = 82/15
y = -98/15