Question

Найдите неизвестный член пропорции: а) 12х=16:36;
б) 5,1:3,4=х:1,4;
в) х:21=5,15;
г) х:2,4=4,5:6

Answer 1

А)

$12x = 16 \div 36 \\ 16x = 12 \times 36 \\ 16x = 432 \\ x = 432 \div 16 \\ x = 27$

Б)

$5.1 \div 3.4 = x \div 1.4 \\ 3.4x = 5.1 \times 1.4 \\ (34/10)x = 51/10 \times 14/10 \\ (34/10)x = 357/50 \\ x = 357/50 \div 34/10 \\ x = 357/50 \times 10/34 \\ x = 21/10 \\ x = 2.1$

В)

$x \div 21 = 5.15 \\ x = 21 \times 5.15 \\ x = 21 \times 515/100 \\ x = 10815 \div 100 \\ x = 108.15$

Г)

$x \div 2.4 = 4.5 \div 6 \\ 6x = 2.4 \times 4.5 \\ 6x = 24/10 \times 45/10 \\ 6x = 108 /10 \\ x = 108/10 \div 6 \\ 108/10 \times 1/6 \\ x = 18 \div 10 \\ x = 1.8$