\(\dfrac{3}{4}\) x 36 + 75% x 23 + \(\dfrac{75}{100}\) + 0,75 x 40
= ..... x 36 + ....... x 23 + ..... + 0,75 x 40
= ..... x ( 36 + 23 + 1 + ..... )
= ..... x 100
= .....
23*[(12*x+39):3]=23+40*115
23 * [ ( 12 * x + 39 ) : 3 ] = 23 + 40 * 115
23 x [ ( 12 x x + 39 ) : 3 ] = 4623
( 12 x x + 39 ) : 3 = 4623 : 23
( 12 x x + 39 ) : 3 = 201
12 x x + 39 = 201 x 3
12 x x + 39 = 603
12 x x = 603 - 39
12 x x = 564
x = 564 : 12
x = 47
k mik nha các bn
125-{23+77}+[3x3]-(40+40)=
125 - (23 + 77) + (3x3) - (40+40) = 125 - 100 + 9 - 80
= 34 - 80
= -46
Goodluck!!
\(125-\left(23+77\right)+\left(3\times3\right)-\left(40+40\right)\)
\(=125-100+9-80\)
\(=25+9-80\)
\(=34-80\)
\(=-46\)
_Chúc bạn học tốt_
tính nhanh
2000 - 40 x 27 - 40 x 23
`@` `\text {Ans}`
`\downarrow`
`2000 - 40 \times 27 - 40 \times 23`
`= 2000 - 40 \times (27 + 23)`
`= 2000 - 40 \times 50`
`= 40 \times 50 - 40 \times 50`
`=0`
\(2000-40x27-40x23\)
\(=40x50-\left(40x27+40x23\right)\)
\(=40x50-\left[40x\left(27+23\right)\right]\)
\(=40x50-40x50=0\)
23 x X [ ( 12 x X + 39 ) ] : 3 = 23 + 40 x 115
Ta có: 23. [(12.X+39):3] = 4623
⇒(12.X+39):3 = 201
⇒12.X+39 = 603
⇒12.X = 564
⇒X = 47
tinh nhanh s= 20*21+22*23+23*24+24*25+...+39*40
Tính nhẩm:
40 + 8 = … | 30 + 5 = … | 23 + 6 = … | 65 + 3 = … |
60 + 1 = … | 90 + 2 = … | 23 + 60 = … | 3 + 65 = … |
Lời giải chi tiết:
40 + 8 = 48 | 30 + 5 = 35 | 23 + 6 = 29 | 65 + 3 = 68 |
60 + 1 = 61 | 90 + 2 = 92 | 23 + 60 = 83 | 3 + 65 = 68 |
40-23=?
=17 dễ quá1111111111111111111111111111111111111111111111111111111111111
1. so sánh A và B . biết : A =\(\frac{23^{40}+1}{23^{41}+1}\);B =\(\frac{23^{41}+1}{23^{42}+1}\)
\(B=\frac{23^{41}+1}{23^{42}+1}\)
Vì B < 1
\(\Rightarrow B=\frac{23^{41}+1}{23^{42}+1}< \frac{23^{41}+1+22}{23^{42}+1+22}=\frac{23^{41}+23}{23^{42}+23}=\frac{23(23^{40}+1)}{23\left(23^{41}+1\right)}=\frac{23^{40}+1}{23^{41}+1}=A\)
P/s: Hoq chắc
ta có
\(B=\frac{23^{41}+1}{23^{42}+1}< \frac{23^{41}+1+22}{23^{42}+1+22}=\frac{23^{41}+23}{23^{42}+23}=\frac{23\left(23^{40}+1\right)}{23\left(23^{41}+1\right)}=\frac{23^{40}+1}{23^{41}+1}=A\)
\(\Rightarrow B< A\)