Question

даю 30 баллов
1)-1/2-1/4=?
2)-1/5-1/10=?
3)-2/9-(-1/3)=?
4)3/8-3/4=?
5)-1/5-2/15=?
6)3/7-(-1/14)=?​

Answer 1

$1)(-\frac{1}{2})-\frac{1}{4} =\frac{(-2)*1-1*1}{4} =-\frac{3}{4} =-0,75$

$2)(-\frac{1}{5}) -\frac{1}{10} =\frac{(-1)*2-1*1}{10} =-\frac{3}{10} =-0,3$

$3)(-\frac{2}{9} )-(-\frac{1}{3}) =(-\frac{2}{9} )+\frac{1}{3} =\frac{(-2)*1+1*3}{9}=\frac{-2+3}{9} =\frac{1}{9}$

$4)\frac{3}{8} -\frac{3}{4} =\frac{3*1-3*2}{8}=\frac{3-6}{8} =-\frac{3}{8} =-0,375$

$5)-\frac{1}{5} -\frac{2}{15} =\frac{(-1)*3-2*1}{15} =\frac{-3-2}{15} =-\frac{5}{15} =-\frac{1}{3}$

$6)\frac{3}{7} -(-\frac{1}{14}) =\frac{3}{7} +\frac{1}{14} =\frac{3*2+1*1}{14} =\frac{7}{14} =\frac{1}{2}=0,5$