Môn Toán Lớp 7: a,2x-3=0 b,3x2=8-x-7x c,x²-9=(2x1)(x-3) d,4x/35x/2=1 e,3/x4x1/x-2=12x-10/x(x-2)

Question

Môn Toán Lớp 7:  a,2x-3=0 b,3x+2=8-x-7x c,x²-9=(2x+1)(x-3) d,4x/3+5x/2=1 e,3/x+4x+1/x-2=12x-10/x(x-2)

truonganhthi · Answer

trả lời+giải th&iacute;ch:      a, 2$x$-3=0     &hArr;2$x$=3     &hArr; $x$=$ frac{3}{2}$      b, 3$x$+2=8-$x$-7$x$     &hArr;3$x$+$x$+7$x$=8 - 2      &hArr;10$x$=6     &hArr;$x$ =$ frac{6}{10}$      &hArr;$x$=0,6     c , $x^2$-9=(2$x$+1)($x$-3)        &hArr;$x^        2$         &minus;    9  =$    2   x^2$   &minus;    5$  x$  &minus;    3         &hArr;&minus;$   x^2$   &minus;    9  =    &minus;  5$  x$  &minus;    3         &hArr;&minus;$ x^2$  &minus; 9 + 5$ x$  + 3 = 0         &hArr;&minus;$ x^2$  + 5$ x$  &minus; 6 = 0(casio)             &hArr;$ left[ begin{matrix} x=2   x=3 end{matrix} right.$           d,$ frac{4x}{3}$ +$ frac{5x}{2}$ =1     &hArr;$ frac{4x*2}{3}$ +$ frac{5x*3}{2}$ =1*6       &hArr;2  &times;    4$  x$  +    3  &times;    5$  x$  =    6         &hArr;8$ x$  + 15$ x$  = 6         &hArr;23$ x$  = 6         &hArr;$x$=$ frac{6}{23}$          e,$ frac{3}{x+4x}$ +$ frac{1}{x-2}$ =  $ frac{12x-10}{x(x-2)}$          &hArr;($  x$  &minus; 2 )   &times; 3 + 5$ x$  = 5  ( 12$ x$  &minus; 10 )            &hArr;3$ x$  &minus; 6 + 5$ x$  =  60$ x$  &minus; 50           &hArr;8$ x$  &minus; 6 =  60$ x$  &minus; 50           &hArr;8$ x$  &minus; 6 &minus; 60$ x$  = &minus;50          &hArr;&minus;  5  2$  x$  =    &minus;  5  0  +    6         &hArr;&minus;  5  2$  x$  =  &minus;44         &hArr;$x$=$ frac{-44}{-52}$          &hArr;$x$=$ frac{11}{13}$                                                             bn tham khảo nha                                                       Ch&uacute;c bn học tốt          #naziok6                                  Cho xin hay nhất nha

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