\(155-\frac{25}{2}\times4\times\frac{1}{10}+x\div\frac{3}{4}=200\)
\(\rightarrow155-5+x\div\frac{3}{4}=200\)
\(\rightarrow150+x\div\frac{3}{4}=200\)
\(\rightarrow x\div\frac{3}{4}=200-150\)
\(\rightarrow x\div\frac{3}{4}=50\)
\(\rightarrow x=50\times\frac{3}{4}\)
\(\rightarrow x=\frac{75}{2}\)
Vậy \(x=\frac{75}{2}\)
Câu 1. Tính theo cách thuận tiện nhất:
25 x 96 x 4 x 2 ...................................................................................................................................................... 155 x 42 + 155 x 58 .................................................................................................................................................... 461 x 35 + 35 x 539 196 x 73 + 196 x 27 ...................................................................................................................................................... .....................................................................................................................................................
a)2+2+4+6+10+.......+68
b)(x+1)+(x+4)+(x+7)+......(x+28)=155
Tìm X :
a, (X + 1) + (X + 4) + (X +7) +(X + 10) + . . . + (X + 28) = 155
1.Tính tổng
a,1+2+3+4+......+999=?
b,21+23+25+.....+1001=?
c,23+24+25+.....+127+128=?
d,15+17+19+21+......+151+153+155=?
Tìm X :
a, (X + 1 ) + (X + 4 ) + (X + 7 ) + (X + 10 ) + ... + (X + 28 ) = 155
Bài 299: Tính
1) 1/3 x 1/2 x 3/7
2) 5/4 x 1/3 + 1/7
3) 8 x ( 8/9-2/3 )
4) 5/6 x 48/20 x 1/2
5) ( 2/5 + 3/4 ) x 8
6) 10 x ( 1/2-1/5 )
Trình bày rõ cách làm giúp nhen!!
Tính bằng cách thuận tiện nhất a)2+4+6+...+20+22+24 b)150+155+160+...+200+205
Tính nhanh:
a) (1/2 : 50% - 1/4 : 25% + 1/8 : 12,5 - 1/10 : 10%) : 1 + 2 + 3 + ... 2006 + 2007 + 2008)
c) 8,1 : 0,6 x 1875 + 1,5 x 625 x 9
1) 444 x 5 = 222 x 2 x 5 = 222 x 10 = 2220
a.Đúng b.Sai
2) 282 x 5 = 280 + 2 x 5 = 280 x 10 = 2800
a.Đúng b. Sai
3) 4 x 8 x 7 x 25 = (8 x 7) x (25 x4) = 56 x 100 = 5600
a.Đúng b.Sai
4) 25 x 8 x 9 = (25 x 4) x (4 x 9) = 100 x 36 = 3600
a.Đúng b.Sai