Question

Помогитег0псщначнашчнчщнас8несче​

Answer 1

Ответ:

Пошаговое объяснение:

7. (2 1/2 +1 1/3)/(2 1/2 -1 1/3) -2/7=(3*5/(3*2) +2*4/(2*3))/(3*5/(3*2) -2*4/(2*3)) -2/7=(15+8)/6 *6/(15-8) -2/7=23/7 -2/7=21/7=3

8. 5 6/7 +4 5/6 -7 7/8=5 (6*6)/(6*7) +4 (7*5)/(7*6) -7 7/8=9 (36+35)/42 -7 7/8=10 29/42 -7 7/8=10 (4*29)/(4*42) -7 (21*7)/(21*8)=9 (168+116)/168 -7 147/168=2 (284-147)/168=2 137/168

9. (1 2/3 +2 3/4 +3 4/5) *15/493=(1 (4*2)/(4*3) +2 (3*3)/(3*4) +3 4/5) *15/493=(3 (8+9)/12 +3 4/5) *15/493=(4 (5*5)/(5*12) +3 (12*4)/(12*5)) *15/493=7 (25+48)/60 *15/493=(420+73)/(4*493)=493/(4*493)=1/4 или 0,25

10. (2 4/5 +3 5/6 -5 6/7) :1/70 -50=(2 (6*4)/(6*5) +3 (5*5)/(5*6) -5 6/7) :1/70 -50=(5 (24+15)/30 -5 6/7) :1/70 -50=(6 (7*3)/(7*10) -5 (10*6)/(10*7)) :1/70 -50=(70+21-60)/70 *70-50=91-60-50=31-50=-19