решить уравнения

2.75 / (1/4+2/5x) = 1/2

(2/3x+20*3/2) = 43.3

2.75 / (1/4+2/5x) = 1/2

1/4+2/5 х=2,75:1/2

1/4+2/5 х=11/2

2/5 х=11/2-1/4

2/5 х=21/4

х=21/4:2/5

х=105/8=13,125

(2/3x+20*3/2) = 43.3

2/3 х+30=43,3

2/3 х=43,3-30

2/3 х=13,3

х=13,3:2/3

х=399/20=19,95