1/51 и 1/68 = 1/(3*17) и 1/(4*17) = 4/204 и 3/208
5/36 и 7/54 = 5/(2*2*9) и 7/(2*3*9) = 15/108 и 14/108
9/35 и 11/42 = 9/(7*5) и 11/(7*6) = 54/210 и 55/210
4/49 и 5/63 = 4/(7*7) и 5/(7*9) = 36/441 и 35/441
15/98 и 13/72 = 15/(2*49) и 13/(2*36) = 540/3528 и 637/3528
1) -( tg 35° + tg 10°)/ (-1 + tg 35°tg10°) = (tg35°+ tg10°) /(1-tg35° tg10°) = tg (35°+10°) = tg 45° = 1
2) (tg10°-tg35°) /(1+tg10° tg35°) = tg (10°-35°) = tg (-25°) = - tg 25°
<span> 598 + 980 / 7 - 560 / 4=598</span>
1) 220 + 300 = 520 520:10 = 52
2) 105+510 = 615 615:5 = 123
3) 770+220 = 990 990:11 = 90