Chiều dài hình chữ nhật sau khi tăng là :
100 + 20 = 120 % = 1,2
Chiều rộng sau khi giảm là :
100 - 20 = 80 % = 0,8
Diện tích ban đầu của hình chữ nhật là :
80,32 : [ 1- ( 1,2 x0,8 ) ] = 2008 cm2
ĐS : 2008 cm2
Giải:
Diện tích HCN mới sau khi đã tăng, giảm là:
(100% + 20%) x (100% - 20%) = 96% (Diện tích ban đầu)
30% chiếm số phần diện tích ban đầu là: 100% - 96% = 4%
Diện tích ban đầu là: 30 : 4% = 750 m2
2008cm2 bản nhé thằng nào ra 750cm2 là thằng ý nguuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
2008
ai tk mk
mk tk lại
hứa luôn
thank you