- 7( 0,3х - 8 ) + 3( 0,4х + 5 ) = 8
- 2,1х + 56 + 1,2х + 15 = 8
- 0,9х = 8 - 71
х = - 63 : ( - 0,9 )
х = 70
3 1/2 + 1 = 7/2 + 1 =(7 *1 + 1 *2)/2 = 7/2 + 2/2 = 9/2 = 4 1/2
4 + 1 1/3 = 4 + 4/3 =(4 * 3 + 4 * 1)/3 = 12/3 + 4/3 = 16/3 = 5 1/3
3 1/2 + 7/12 = 7/2 + 7/12 =(7 * 6+7 *1)/12 = 42/12 +7/12 = 49/12 = 4 1/12
5 3/7 + 9/14 = 38/7+9/14 =(38 * 2+9*1)/14 = 76/14+9/14 = 85/14 = 6 1/14
4 3/5 + 2 = 23/5 + 2 =(23 * 1 + 2 * 5)/5 = 23/5 + 10/5 = 33/5 = 6 3/5
4 1/6 + 3 11/12 = 25/6+47/12 =(25 * 2+47 *1)/12 = 50/12+47/12 =97/12 = 8 1/12
2 3/10+4/15=23/10 + 4/15 = (23* 3 + 4 * 2)/30 = 69/30 + 8/30 = 77/30 = 2 17/30
9 10/13 +7 7/2 = 127/13+21/2 =(127 * 2+21 *13)/26 = 254/26+273/26 = 527/26 = 20 7/26
1) 26×4=104 (т.)- из 2 стопки;
2)160-104=56(т.)- в 1 стопке;