Bài tập tuần 3 – Toán lớp 7 – THCS Dịch Vọng Hậu

LUYỆN TẬP: NHÂN, CHIA SỐ HỮU TỈ

PHIẾU BÀI TẬP TUẦN 3 – TRƯỜNG THCS DỊCH VỌNG HẬU

Bài 1: Thực hiện phép tính (hợp lí nếu có thể):

a) $left( -frac{28}{19} right).left( frac{-38}{14} right)$

b) $left( -frac{-21}{16} right).left( -frac{24}{7} right)$

c) $frac{12}{25}.frac{23}{7}-frac{12}{25}.frac{12}{7}$

d) $13frac{2}{7}:left( frac{-8}{9} right)+2frac{5}{7}:left( frac{-8}{9} right)$

e) $left( frac{-6}{11} right).frac{7}{10}.left( frac{11}{-6} right).left( -20 right)$

f) $left( -1frac{1}{2} right):frac{3}{4}.left( -4frac{1}{2} right)$

g) $21-3frac{3}{4}:left( frac{3}{8}-frac{1}{6} right)$

h) $left( 2-frac{3}{2} right)left( 2-frac{4}{3} right)left( 2-frac{5}{4} right)left( 2-frac{6}{5} right)$

i) $frac{1}{2011}+frac{2012.2010}{2011}-2012$

k) $frac{5}{4}-frac{5}{4}:left( frac{3}{8}-frac{1}{6} right):frac{11}{12}$

l) $frac{3}{5}:left( -frac{-1}{15}-frac{1}{6} right)+frac{3}{5}:left( frac{-1}{3}-1frac{1}{15} right)$

m) $left( frac{-3}{4}+frac{2}{5} right):frac{3}{7}+left( frac{3}{5}+frac{-1}{4} right):frac{3}{7}$

n) $left( 1-frac{1}{{{2}^{2}}} right)left( 1-frac{1}{{{3}^{2}}} right)left( 1-frac{1}{{{4}^{2}}} right)…….left( 1-frac{1}{{{100}^{2}}} right)$

0) $2+frac{1}{2+frac{1}{2+frac{1}{2+frac{1}{2}}}}$

Bài 2: Tìm x, biết:
a) $1frac{1}{2}x+frac{-4}{5}=4$

b) $frac{2}{3}x+frac{-1}{2}x=frac{-5}{12}$

c) $frac{3}{7}x-frac{2}{3}x=frac{10}{21}$

d) $left( 4frac{2}{3}-2x right).2frac{1}{4}=1frac{1}{2}$ e) $frac{3}{5}+frac{4}{9}:x=frac{2}{3}$

f) $frac{7}{35}:left( x-frac{1}{3} right)=-frac{2}{25}$

g) $frac{3}{5}left( frac{5}{3}-x right)=frac{3}{5}left( frac{2}{3}-frac{1}{9} right)$

h) $frac{3}{4}left( x-8 right)=frac{5}{7}left( 14-frac{7}{2} right)$

i) $3left( x-frac{1}{2} right)-5left( x+frac{3}{5} right)=-x+frac{1}{5}$ k) $left( 2x-1 right)left( x+frac{2}{3} right)=0$

l) $displaystyle frac{x+4}{2011}+frac{x+3}{2012}+frac{x+2}{2013}+frac{x+1}{2014}$

m) $left( x+1 right)left( x+5 right)>0$