Wow good to know. But I’m not seeing a picture
CC. 2 units in positive x and 3 units in positive z
Work out the Greatest Common Factor for both numbers
54 42
1×54 1×42
2×27 2×21
3×18 3×14
6×9 6×7
The common factors are: 1, 2, 3 and 6
The greatest common factor is 6
There are 6 identical arrangements that can be made
(6/8) / (2/6)
(6/8) * (6/2)
(6*6) / (8*2)
36 / 16
9 / 4
2.25
Let Length of each Plan A workout be 
and Length of each Plan B workout be $b$
on Wednesday,
$5a+3b=7$
$2a+12b=19$
multiply equation one by $4$ and subtract equation two from it
to get,
$18a=9$ or $a=\frac12$
substitute $a$ in eq 2. to get $b$, $12b=18\implies b=\frac32$