x+10-20=70-10
x-20+40=40+20
a, 100 . 10 + 200 . 10=?
b, 10 . 20 + 20 . 40=?
A=\(\dfrac{1}{3.6}\)+\(\dfrac{1}{6.9}\)+...+\(\dfrac{1}{123.126}\)=?
50+100+10+50+900=?
30+80+40+70+60+20=?
20+50+40+30+10=?
A=\(\dfrac{1}{5.9}\)+\(\dfrac{1}{9.13}\)+...+\(\dfrac{1}{161.165}\)=?
A=\(\dfrac{1}{3.6}\)+\(\dfrac{1}{6.9}\)+...+\(\dfrac{1}{132.135}\)
A=?
(900-38). 38+(800+62). 62=?
A=\(\dfrac{1}{6.10}\)+\(\dfrac{1}{10.14}\)+\(\dfrac{1}{14.18}\)+...+\(\dfrac{1}{202.206}\)