Quy đồng mẫu các phân thức sau: a,5/3;5a-6/3a b,2x/3;2ax+3x/3a c,b/6a;4a+3b^2/18ab;x/9b d,x/4a;6a-5bx/20ab;a-1/10b e,5/3;5x-1/3(x+1) f,1-x/2(x+1);1/2 g,7/5;7a-31/5a-15 h,3/b-1;7-b/2b-2 i,2/3a;1/2a-2;a-4/6a^2-6a
Quy đồng mẫu các phân thức sau: a,5/3;5a-6/3a b,2x/3;2ax+3x/3a c,b/6a;4a+3b^2/18ab;x/9b d,x/4a;6a-5bx/20ab;a-1/10b e,5/3;5x-1/3(x+1) f,1-x/2(x+1);1/2 g,7/5;7a-31/5a-15 h,3/b-1;7-b/2b-2 i,2/3a;1/2a-2;a-4/6a^2-6a
Đáp án:
$\begin{array}{l}
a)\frac{5}{3} = \frac{{5a}}{{3a}}\,\,\,\,\,\,\,\,\,\,\,\,\frac{{5a – 6}}{{3a}}\\
b)\frac{{2x}}{3} = \frac{{2ax}}{{3a}}\,\,\,\,\,\,\,\,\,\,\,\,\,\frac{{2ax + 3x}}{{3a}}\\
c)\frac{b}{{6a}} = \frac{{b.3b}}{{18ab}} = \frac{{3{b^2}}}{{18ab}}\,\,\,\,\,\,\frac{{4a + 3{b^2}}}{{18ab}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\frac{x}{{9b}} = \frac{{x.2a}}{{18ab}} = \frac{{2ax}}{{18ab}}
\end{array}$