Solve using elemination method?

3a-3b=12
3a=3b+12
a=b+4

4(b+4)=b+2
4b+16=b+2
3b=-14
b=-14/3

3a-3(-14/3)=12
3a+14=12
3a=-2
a=-2/3

If the numerator and denominator of a fragment are the two decreased via one, the fraction turns into 2/3. If the numerator and denominator are the two greater effective via one, the fraction turns into 3/4. If the unique fraction is x/y: x - a million / y - a million = 2/3 x + a million / y + a million = 3/4 2y - 2 = 3x - 3 3y + 3 = 4x + 4 6y - 9x = -3 6y - 8x = 2 -x = -5 x = 5 y = 7 the unique fraction is 5/7

3(a-b) = 12
3a - 3b = 12 -----------------------------(1)
4a = b + 2
4a - b = 2 ------------------------------(2)
Multiply equation (2) by 3
12a - 3b = 6 ---------------------------(3)
Subtract equations (1) from (3) we get
12a - 3b - ( 3a - 3b) = 6 - 12
12a - 3b - 3a + 3b = -6
9a = - 6
a = - 6/9
a = -2/3 (Answer)
Now sub a = -2/9 in equation (1)
3 (-2/3) - 3b = 12
-2 - 3b = 12
-3b = 12 + 2
-3b = 14/-3
b = - 14/3 (Answer)

3(a-b) = 12
this distributes to
3a - 3b = 12

4a = b+2
subtract b from each side
4a - b = 2
multiply each side by -3
-3(4a-b) = -3*2
-12a + 3b = -6

now take the two equations and make an addition expression out of them
3a - 3b = 12
-12a + 3b = -6
add them up: the a's to the a's, the b's to the b's, etc. Note that the b's cancel out (-3 and +3)
-9a = 6
divide each side by -9
a = -(6/9) = -(2/3)

now put this value of a into one of the equations to solve for b
4(-2/3) = b+2
-(8/3) = b + 2
subtract 2 from each side
b = -(14/3)

check it in the other equation
3(-2/3-(-14/3)) = 12
3(12/3) = 12 that works!

a-b=4 ,a=4+b, 4(4+b)=b+2, 16+4b=b+2, 3b=-14, b=-14/3
a-b=4,a=4+b,a=4-14/3=-2/3
God bless you.

3(a - b) = 12
4a = b + 2

3(a - b) = 12
a - b = 12/3
a - b = 4 ...... (1)

4a = b + 2
4a - b = 2 ...... (2)

Subtract (2) from (1).
.....a - b = 4
‒ 4a - b = 2
------------------------
..-3a .....= 2

-3a = 2
a = 2/(-3)
a = -2/3

a - b = 4

Substitute -2/3 for a.
-2/3 - b = 4
b = -2/3 - 4
b = -2/3 - 12/3
b = -14/3

∴ a = -2/3, b = -14/3