45 ! уравнения: x+2/-2,3 = -5,1/1,7 2(1 1/7 - x) - 3 1/14 = -2 5/7 -1,6/x-2 = -2,8/4,2 4,9/x - 2 = 21/15 x+ 4= 5 найдите значения выражения: (-5/12 - 13/20)*(-1 13/32) (-2/3 - 5/6)*(-3 5/9)

х+2/-2,3= -5,1/1,7

х-20/23= -3

х=20/23-69/23= -49/23= -2 3/23

2(1 1/7-х)-3 1/14= -2 5/7

2(8/7-х)=43/14-19/7

16/7-х=43/14-38/14

32/14-х=5/14

х=32/14-5/14=27/14=1 13/14

-1,6/х-2= -2,8/4,2

-1,6/х=4,2/2,1-1,4/2,1=2,8/2,1

х= -1,6×2,1/2,8= -336/28= -12

4,9/х-2=21/15

4,9/х=21/15+30/15=51/15

х=4,9×15/51=735/510=147/102

х=1 45/102

х+4=5; х=5-4=1

(-5/12-13/20)×(-1 13/32)=(-25/60-39/60)×(-45/32)=64/60× 45/32=(64÷32)/(60÷15)× (45÷15)=2/4× 3=1/2× 3=3/2=1 1/2=1,5

(-2/3- 5/6)×(-3 5/9)=(-4/6- 5/6)×(-32/9)=9/6× 32/9=32/6=16/3=5 1/3