52б. 1)1/x+3÷2 2/5=3/4 2)1/x-2÷4 2/3x=2/7

ответ:
1)
(1/x+3)/2*2/5=3/4    
(1/x+3)*5/12=3/4       |12(x+3)
12*5(x+3)=9(x+3)
60x+180=9x+27
60x-9x=27-180
51x=-153
x=-153/51
x=-3
2)
(1/x-2)/4*2/3x=2/7
(1/x-2)*3/14x=2/7  |14x(x-2)
14x*3(x-2)=4x(x-2)
42x(x-2)=4x^2-8x
42x^2-84x=4x^2-8x
42x^2-4x^2=-8x+84x
38x^2=76x
38x^2-76x=0
38x(x-2)=0
x1=0
x2=2