Multiply both sides by -7/4

5(-7/4) = x

-35/4 = x

2/3y = 12

Multiply both sides by 3/2

y = (3/2)(12)

y = 36/2

y = 18

As for 2/3y=1 I am assuming you mean (2/3)y=1 and not 2/(3y)=1??

Anyway, if it is the first and not the second, just take the reciprocal of 2/3 and multiply through. This will cause the coefficient of y to become one and you will have your solution. If it is the second, then you would solve it a bit differently (but using the same idea in that you want to get rid of fractions if at all possible in equations to make life easier). You would multiply through by 3y to clear the fraction leaving you with 2=3y and then solve it from there.

2/3y=1, both side times 3y

2=3y. both side divide by 3

2/3=y

y=2/3, write the answer like this

he can say 5= -4/7x