Question

Найдите неизвестный член пропорции 1) x:20=2:5 2)x:18=7:9​

Answer 1

$x \div 20 = 2 \div 5 \\ x5 = 20 \times 2 \\ x5 = 40 \\ x = 40 \div 5 \\ x = 8 \\ \\ x \div 18 = 7 \div 9 \\ x9 = 18 \times 7 \\ x9 = 126 \\ x = 126 \div 9 \\ x = 14$

Answer 2

Ответ:

1)

x:20=2:5

x/20=2/5=0,4

x/20=0.4

×=20*0.4=8

2)

x:18=7:9

x=7/9×18/1=14