1) 9 - 4 2/17 + 2 3/17 = 8 17/17 - 4 2/17 + 2 3/17= 4 15/17 + 2 3/17 = 6 18/17 = 7 1/17
2) 5 3/5 - 2 6/11 +3 3/5 = 5 3/5 + 3 3/5 - 2 6/11 = 9 1/5 - 2 6/11 = 9 11/55 - 2 30/55 = 6 36/55
3) 4 3/8+3 7/8-1 3/7 = 8 1/4 - 1 3/7 = 7 1/4 - 3/7 = 29/4 - 3/7 = 203/28 - 12/28 = 191/28 = 6 23/28
4) 20-3 8/15+10 4/15 = 19 15/15 - 3 8/15 + 10 4/15 = 26 11/15
1) 8 × 100= 800; 2.6 × 100 =260
2) 6 ×50 = 300; 3.4 × 50 = 170;
3) 0.8×10=8; 2.2×10=22;
4) 12×5=60; 30 ×5= 150;
5)8 × 4 = 32; 12 ×4 = 48;
6)90×2=180; 0.3×2=0.6
15(17-6). 15•11. 11
______ = _____= ___
15(17+6). 15•23. 23
81•(17-15) 81•2. 2
_______ = ____ = __
81•(17+4). 81•21. 21
R=S/p, где p -полупериметр и p=(14+10)/2=12
Пусть один катет х, второй (14-х)
х²+(14-х)²=10² ⇒х²+196-28х+х²=100 ⇒2х²-28х+96=0 ⇒х²-14х+48=0
х=8 или х=6
r=8·6/2 / 12=2