U is 10. If you subtract 11 first to get the variable and it's coefficient on its own, you see that 3u=30. To get the u on its own, you divide both sides by three. This gives you u=10
Same question x+y=30 x is 1/5 of y x=y/5 subsitute y/5+y=30 multily both sidse by 5 y+5y=150 add 6y=150 divide both sides by 6 y=25 subsitute x=y/5 x=25/5 x=5 the numbers are 5 and 25
