Найти значение выражения: а) 2/5 m, если m=1/2; 2/5; 2целых1/2; 1целая 7/8; 15/16; б) 4/9 х,еслих=1/4; 4/9 4целых 1/2

а) 2/5 * m

m = 1/2

2/5 * 1/2 = 1/5 = 0,2

m = 2/5

2/5 * 2/5 = 4/25 = 0,16

m = 2 1/2

2/5 * 2 1/2 = 2/5 * 5/2 = 1

m = 1 7/8

2/5 * 1 7/8 = 2/5 * 15/8 = 3/4 = 0,75

m = 15/16

2/5 * 15/16 = 3/8 = 0,375

б) 4/9 * x

x = 1/4

4/9 * 1/4 = 1/9

x = 4/9

4/9 * 4/9 = 16/81

x = 4 1/2

4/9 * 4 1/2 = 4/9 * 9/2 = 2