( 66 + x ) - 53 = 66 - 53 + x = 13 + x
1).8=2×2×2
16=2×2×2×2
НОК:8,16=16
2).30=2×3×5
45=3×3×5
НОД:30,45=15
1 3/11:2/9=7 2/10:1 9/35
14/11:2/9=72/10:44/35
14/11*44/35=72/10*2/9
8/5=8/5
Пропорция верная