Question

substitute the given value 4 (5y/6)-3y=4​

Answer 1

you can do this in the scientific calculator

Answer 2

Since you have two simultaneous equations; let's make one of the unknowns similar.

3x + 5y = 6

2x - 3y = 4

lets make both the y's in both the equations similar. We multiple the whole of first equation with 3 and we multiple the whole of second equation with 5and you will get;

9x + 15y = 18

10x - 15y = 20

so from the above we can add equation 2 to equation 1 to rule out the Unknown y

9x + 15y = 18……….. (+)

10x - 15y = 20

so you get 19x = 38, hence x=2.

When x = 2, y = 0.

You can also cross check your answer if you do it in terms of y first, to see whether your answer matches.