(7/6+0,25+1,1/4):2,2/3;( 1,1*2,5/0,25-1,5)/8*2/5-6,3; (3,2-1,7)/х+х/3 прих=1,5 и 3

1) (7/6 + 0,25 + 1 1/4) : 2 2/3 = (7/6 + 1/4 + (1 * 4 + 1)/4) : (2 * 3 + 2)/3 = (7/6 + 1/4 + 5/4) : 8/3 = ((7 * 4)/24 + 6/24 + (5 * 6)/24) * 3/8 = (28/24 + 6/24 + 30/24) * 3/8 = ( 28 + 6 + 30)/24 * 3/8 = 64/24 * 3/8 = 8/3 * 3/8 = 1.

2) (1,1 * 2,5/0,25 - 1,5)/8 * 2/5 - 6,3 = (2.75/0.25 - 1.5)/8 * 2/5 - 6.3 = (11 - 1.5)/8 * 2/5 - 6.3 = 9.5/8 * 2/5 - 6.3 = 19/2 * 1/8 * 2/5 - 6.3 = 19/40 - 63/10 = 19/40 - (63 * 4)/40 = 19/40 - 252/40 = (19 - 252)/40 = - 233/40 = - 5.825.

3) Упростим наше выражение.

(3,2 - 1,7)/х + х/3 = 1.5/x + x/3.

Подставим х = 1,5.

1.5/x + x/3 = 1.5/1.5 + 1.5/3 = 1 + 0.5 = 1.5.

Подставим х = 3.

1.5/x + x/3 = 1.5/3 + 3/3 = 1/2 + 1 = 1 + 0.5 = 1.5.