a) make the equations, so they don't have fractions.
for example, first line (x/3) + (y/4) = 11
times it by 3 and 4, so we have 4x+3y = 132
b) 6x + 5y = 2(x + 6y -1)
7x + 3y + 1 = 2(x + 6y -1)
2(x + 6y -1)=2x+12y-2
put all the x and y on one side.
for example, the first line would be 4x-7y=-2