1)y-4/7y=4,2 2) x-7/9x=3,6
1) 7/7y-4/7y=4.2
3/7y=4.2
y=4.2 : 3/7
y=9,8
2)
9/9x - 7/9x=3.6
2/9x=3,6
х=16,2
1) y - 4y/7 = 21/5
(7y - 4y)/7=21/5
3y*5=7*21
y=49/5
2) x-7x/9 = 18/5
(9x - 7x) / 9=18/5
2x * 5=18 * 9
x=81/5