13*27+26*35+13*4-13 = ?
a) 21/47 + 9/45 +26/47 + 4/5
= (21/47 + 26/47) + (9/45 + 4/5)
=1+1 = 2
b) 15/12 + 5/13 - 3/12 - 18/13
= (15/12 - 3/12) + (18/13 - 5/13)
=1+1 = 2
c) 13/25 + 6/41 - 38/25 + 35/41 - 1/2
= (38/25 - 13/25) + (35/41 + 6/41) + 1/2
= 1+1 + 1/2 = 5/2
d) 27/23 + 5/21 - 4/23 + 6/21 + 1/2
= (27/23 - 4/23) + (6/21 - 5/21) + 1/2
= ..........................
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(-3/4+2/3):5/11+(-1/4+1/3):5/11
a)|x-13|-35-45=-47
b)(4+x).(x+3)=0
c)25-(5-x)=120-(28-5)
5/13 x 9/14 x 28/27 x 26/35
\(\dfrac{5}{13}\) \(\times\) \(\dfrac{9}{14}\) \(\times\) \(\dfrac{28}{27}\) \(\times\) \(\dfrac{26}{35}\)
= \(\dfrac{5}{13}\) \(\times\) \(\dfrac{9}{14}\) \(\times\) \(\dfrac{14\times2}{9\times3}\) \(\times\) \(\dfrac{13\times2}{5\times7}\)
= \(\dfrac{5\times9\times14\times13}{5\times9\times14\times13}\) \(\times\) \(\dfrac{2\times2}{3\times7}\)
= 1 \(\times\) \(\dfrac{4}{21}\)
= \(\dfrac{4}{21}\)
tính nhanh :
a) 13 x 27 + 26 x 35 + 13 x 4 - 13
b) ( 11 x 9 - 100 + 1 ) : ( 1 x 2 ....... x 10 )
AI TRẢ LỜI NHANH , ĐÚNG NHẤT VÀ GIẢI RÕ RÀNG THÌ ĐƯỢC LIKE
a, =13x(27+2x35+4-1)=13x100=1300
b, =(99-99):(1x2x...x10)=0
tick nha!
Tính các tổng sau một cách hợp lí
a ) 1 3 + − 2 6 + 3 9 ; b ) − 4 12 + 18 45 + − 6 9 + 24 30 ; c ) 7 23 + − 10 18 + − 4 9 + 16 23 + − 5 8 ; d ) 1 3 + − 3 4 + 3 5 + − 1 36 + 1 15 + − 2 9 e ) − 1 2 + 3 5 + − 1 9 + − 7 18 + 4 35 + 2 7
a) 1 3 + − 1 3 + 1 3 = 1 3
b ) − 1 3 + 2 5 + − 2 3 + 4 5 = 1 5 c ) 7 23 + 16 23 + − 5 9 + − 4 9 + − 5 8 = − 5 8 d ) − 2 9 + − 3 4 + − 1 36 + 1 3 + 3 5 + 1 5 = 0 e ) − 1 2 + − 1 9 + − 7 18 + 4 35 + 3 5 + 2 7 = 0
Tính nhanh
a, 126 . ( -43 ) + 26 . 43
b, ( -135 ) . ( -45 ) - 35 . 45
c, 113 . ( -27 ) + 27 . 13
d, 125 . ( -35 ) - ( -25 ) . 35
a)126.(-43)+26.43=43(-126+26)=43(-100)=-4300
b)(-135)(-45)-35.45=-45(-135+35)=-45(-100)=4500
c)113(-27)+27.13=27(-113+13)=27(-100)=-2700
d)125(-35)-(-25).35=-35(125-25)=-35.100=-3500
\(a)126.\left(-43\right)+26.43\)
\(=\left(-126\right).43+26.43\)
\(=43\left(-126+26\right)\)
\(=43.\left(-100\right)\)
\(=-4300\)
\(b)\left(-135\right).\left(-45\right)-35.45\)
\(=135.45-35.45\)
\(=45\left(135-35\right)\)
\(=45.100\)
\(=4500\)
\(c)113.\left(-27\right)+27.13\)
\(=\left(-113\right).27+27.13\)
\(=27\left(-113+13\right)\)
\(=27.\left(-100\right)\)
\(=-2700\)
\(d)125.\left(-35\right)-\left(-25\right).35\)
\(=\left(-125\right).35-\left(-25\right).35\)
\(=35\left(-125+25\right)\)
\(=35.\left(-100\right)\)
\(=-3500\)
1, 2x - 35 = 15
2, 3x + 18 = 12
3, /x - 1/ =0
4, -13 /x/ = -26
5, 4 - (27 -3 ) = x - (13 -4)
6, 47 - ( x + 15 ) = 21
7, -5 - ( 24 - x ) = -11
8, 6 - /x/ = 2
9, 6 + /x/ = 2
1, 2x - 35 = 15
2x = 15 + 35
2x = 50
x = 50 : 2
x = 25.
2, 3x + 18 = 12
3x = 12 - 18
3x = -6
x = -6 : 3
x = -2.
3, / x - 1 / = 0
=> x \(\in\varnothing\).
4, -13 /x/ = - 26
/x/ = -26 : -13
=> \(\orbr{\begin{cases}x=2\\x=-2\end{cases}}\)
Vậy x \(\in\){ 2 ; -2}.
5,4 - ( 27 - 3 ) = x - ( 13 - 4 )
4 - 24 = x - 9
-20 = x - 9
-x = 9 + 20
-x = 29
x = -29.
6, 47 - ( x + 15 ) = 21
47 - x - 15 = 21
-x - 15 = 21 - 47
-x - 15 = -26
-x = -26 + 15
-x = - 11
x = 11.
7, -5 -( 24 - x) = - 11
-5 - 24 + x = -11
-24 + x = -11 + 5
-24 + x = -6
x = -6 + 24
x = 18.
8, 6 - /x/ = 2
/x/ = 6 - 2
\(\orbr{\begin{cases}x=3\\x=-3\end{cases}}\)
Vậy x \(\in\left\{3;-3\right\}.\)
9, 6 + /x/ = 2
/x/ = 2 - 6
=> x = -4.
2x - 35 = 15
=> 2x = 15 + 35
=> x = 50 : 2
=> x = 25
3x + 18 = 12
=> 3x = 12 - 18
=> x = ( -6 ) : 3
=> x = -2
| x - 1 | = 0
=> x - 1 = 0
=> x = 0 + 1
=> x = 1
-13 * | x | = -26
=> | x | = -26 : ( -13 )
=> | x | = 2
-10/3 + 13/10-1/6+7/10
1-20/6 +39/30-4/24+34/50
15/24-6/26+28/48-30/39+10/24
-5/10+12/28-3/27-7/18+20/35
tính
A,35 [14-23] - 23 [14-35]
B,27 [13-16] - 16 [13-27]
1.(x+1)/35 + (x+3)/33 = (x+5)/33 + (x+7)/20
2. (X+1)/12+ (X+2)/13 = (X+3)/14+ (X+4)/15
3. (X-85)/15+ (X-75)/13+(X-67)/11+ (X-64)/9=10
4. (X-1)/13-(2X-13)/15=(3X-15)/27- (4X-27)/29
2: \(\Leftrightarrow\left(\dfrac{x+1}{12}-1\right)+\left(\dfrac{x+2}{13}-1\right)=\left(\dfrac{x+3}{14}-1\right)+\left(\dfrac{x+4}{15}-1\right)\)
=>x-11=0
=>x=11
3: \(\Leftrightarrow\left(\dfrac{x-85}{15}-1\right)+\left(\dfrac{x-74}{13}-2\right)+\left(\dfrac{x-67}{11}-3\right)+\left(\dfrac{x-64}{9}-4\right)=0\)
=>x-100=0
=>x=100