Помогите решить уравнения под номером 170

а) 72/5·(-19/54)·15/38·1/х=-64/31·62/5·15/321/х=(-64/31·62/5·15/32) : (72/5·(-19/54)·15/38== -64/31·62/5·15/32·5/72·(-54/19)·38/15= 2/1·2/1·1/72·(-54/19)·38/1== 2/1·2/1·1/4·3/1·2/1=3·2=61/х=6    х=1/6б) 13/12·46/5·(-25/23)=33/17·(-4/81)·51/22·(-х)х=(13/12·46/5·25/23) : (33/17·4/81·51/22)= =13/12·46/5·25/23·17/33·81/4·22/51==13/12·2/1·5/1·17/11·27/4·22/51=13/12·5/1·17/1·27/1·1/51==13/4·5/1·17/1·3/1·1/17=13/4·15/1=195/4=48 3/4х=48 3/4