PHIẾU BT SỐ 24: QUY TẮC DẤU NGOẶC VÀ QUY TẮC CHUYỂN VẾ
Bài 1: Tính tổng sau một cách hợp lí:
a) 215+left(−38right)−left(−58right)+90−85
b) 917−left(417−65right)
c) 31−left[26−left(2017+35right)right]
d) 54+left(−37+10−54+67right)
e) left(326−43right)+left(174−57right)
f) left(351−875right)−left(125−149right)
g) −418−left−218−left[−118−left(−131right)right]+2017right
h) left(−2right)+7+left(−12right)+17+…+left(−52right)+57
i) left(−30right)+left(−29right)+…+48+49+50
Bài 2: Rút gọn các biểu thức sau:
a) A=left(71+xright)−left(−24−xright)+left(−35−xright)
b) B=x−34−left[left(15+xright)−left(23−xright)right]
c) C=left(−15+left|xright|right)+left(25−left|−xright|right)
Bài 3: Tìm số nguyên x, biết:
a) left(−x+31right)−39=−69+11
b) −129−left(35−xright)=55
c) left(−37right)−left|7−xright|=−127
d) left|x−14right|+left(−6right)<−4
e) 43+left(9−21right)=315−left(x+315right)
f) −7+left|x−4right|=−3
g) left(15−xright)+left(x−12right)=7−left(−5+xright)
h) x−left57−left[42+left(−23−xright)right]right=13−left47+left[25−left(32−xright)right]right