В) (х-5):0,7 = (2х-9):0,4;г) х:(3,8-х) = х:(5,6-3х).P.S. Заранее спасибо!

(х-5):0,7 = (2х-9):0,40,4*(х-5) = 0,7*(2х-9)0,4х - 2 = 1,4х - 6,3х = 4,3х:(3,8-х) = х:(5,6-3х)3,8-х = 5,6-3х2х=1,8х=0,9

в)[latex] frac{x-5}{0,7}= frac{2x-9}{0.4} \ (x-5)0.4=(2x-9)0.7 \ 0.4x-2=1.4x-6.3 \ 0.4x-1.4x=2-6.3 \ -x=-4.3 \ x=4.3[/latex]г)[latex] frac{x}{3.8-x}= frac{x}{5.6-3x} \ 3.8-x eq 0; 5.6-3x eq 0 \ x(5.6-3x)=x(3.8-x) \ 5.6x- 3 x^{2} =3.8x- x^{2} \ -3 x^{2} + x^{2} -3.8x+5.6x=0 \ -2 x^{2} +1.8x=0 \ 2 x^{2} -1.8x=0 \ x(2x-1.8)=0 \ x_{1}=0 \ x_{2} =0.9 [/latex]