Bài 6: Tính:
a) (- 13). 34 - 87. 34
b) 74. (- 41) - 41. 26
c) 125. (- 24) + 24. 225
d) 237. (- 26) + 26. 137
e) 63. (- 25) + 25. (- 23)
f) 29. (- 13) + 27. (- 29)
g) - 127. 57 + ( - 127) .43
h) 26. (- 125) - 125. (- 36)
Mọi người giúp mình cả đáp án lẫn cách làm nhé ạ! Mình cảm ơn ạ!
a: =34x(-100)=-3400
b: =41(-76-24)=-4100
c: =-24(125-225)=2400
d: =26(-237+137)=-2600
e: =25(-63+23)=25x(-40)=-1000
Tính:
\(\)a) 127 + 29 + 73;
b) 135 + 360 + 65 + 40;
c) 417 - 17 - 299;
d) 981 - 781 + 29.
`a) 127 + 29 + 73`
`= (127+73)+29`
`= 200 + 29`
`= 229`
`c) 135 + 360 + 65 + 40`
`= (135+65)+(360+40)`
`= 200+400`
`= 600`
`c) 417-17-299`
`= (417-17)-299`
`= 400 - 299`
`= 101`
`d) 981-781+29`
`= (981-781)+29`
`= 200 + 29`
`= 229`
a) 127 + 29 + 73 = 229
b) 135 + 360 + 65 + 40 = 600
c) 417 - 17 - 299 = 104
d) 981 - 781 + 29 = 229
Chúc bạn học tốt!! ^^
a)127+29+73)127+29+73
=(127+73)+29=(127+73)+29
=200+29=200+29
=229=229
c)135+360+65+40)135+360+65+40
=(135+65)+(360+40)=(135+65)+(360+40)
=200+400=200+400
=600=600
c)417−17−299)417-17-299
=(417−17)−299=(417-17)-299
=400−299=400-299
=101=101
d)981−781+29)981-781+29
=(981−781)+29=(981-781)+29
=200+29=200+29
=229
đáp án đây nhé
Tính: 29.(-13) + 27.(-29) + (-14)(-29)
29.(-13) + 27.(-29) + (-14)(-29)
= 29(-13) + (-27).29 + 14.29
= 29(-13 - 27 + 14) = 29.(-26) = -754.
Giaỉ các phương trình sau
\(a,\dfrac{x^2-10x-29}{1971}+\dfrac{x^2-10x-27}{1973}=\dfrac{x^2-10x-1971}{29}+\dfrac{x^2-10x-1973}{27}\)\(a,\dfrac{x^2-10x-29}{1971}+\dfrac{x^2-10x-27}{1973}=\dfrac{x^2-10x-1971}{29}+\dfrac{x^2-10x-1973}{27}\)
a) Ta có: \(\dfrac{x^2-10x-29}{1971}+\dfrac{x^2-10x-27}{1973}=\dfrac{x^2-10x-1971}{29}+\dfrac{x^2-10x-1973}{27}\)
\(\Leftrightarrow\dfrac{x^2-10x-29}{1971}-1+\dfrac{x^2-10x-27}{1973}-1=\dfrac{x^2-10x-1971}{29}-1+\dfrac{x^2-10x-1973}{27}-1\)
\(\Leftrightarrow\dfrac{x^2-10x-2000}{1971}+\dfrac{x^2-10x-2000}{1973}=\dfrac{x^2-10x-1971}{29}+\dfrac{x^2-10x-1973}{27}\)
\(\Leftrightarrow\dfrac{x^2-10x-2000}{1971}+\dfrac{x^2-10x-2000}{1973}-\dfrac{x^2-10x-1971}{29}-\dfrac{x^2-10x-1973}{27}=0\)
\(\Leftrightarrow\left(x^2-10x-2000\right)\left(\dfrac{1}{1971}+\dfrac{1}{1973}-\dfrac{1}{29}-\dfrac{1}{27}\right)=0\)
mà \(\dfrac{1}{1971}+\dfrac{1}{1973}-\dfrac{1}{29}-\dfrac{1}{27}\ne0\)
nên \(x^2-10x-2000=0\)
\(\Leftrightarrow x^2+40x-50x-2000=0\)
\(\Leftrightarrow x\left(x+40\right)-50\left(x+40\right)=0\)
\(\Leftrightarrow\left(x+40\right)\left(x-50\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+40=0\\x-50=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-40\\x=50\end{matrix}\right.\)
Vậy: S={-40;50}
điền số tiếp theo;
4 ; 9 ;29 ;127; ...
1/25×27+1/27×29+1/29×31+…+1/73×75 = ?
91 x 157 - 29 x 91 - 91 x 28
127 x 63 + 19 x 127 - 82 x 26
2 x 9 x 41 + 36 + 3 x 57 x 6
29 x 17 + 31 x 29 + 48 x 93 - 48 x 22
1125 - 25 x 30 + 0,06 : 0,2
THANKS FOR ALL SUPPORTS
91 x 157 - 29 x 91 - 91 x 28
=9100
127 x 63 + 19 x 127 - 82 x 26
=8282
2 x 9 x 41 + 36 + 3 x 57 x 6
=1800
29 x 17 + 31 x 29 + 48 x 93 - 48 x 22
=4800
1125 - 25 x 30 + 0,06 : 0,2
=375.3
Bn k cho mk nha!
91 x 157 - 29 x 91 - 91 x 28
= 19 (157 - 29 - 28)
=19 * 100
=1900
127 x 63 + 19 x 127 - 82 x 26
= 127 (63 + 19) - 82 * 26
= 127 * 82 - 82 * 26
= 82 (127 - 26)
= 82 * 101
= 8282
2 x 9 x 41 + 36 + 3 x 57 x 6
= 738 + 36 + 1026
= 1800
29 x 17 + 31 x 29 + 48 x 93 - 48 x 22
= 29 (17 + 31) + 48 (93 - 22)
= 29 * 48 + 48 * 71
= 48 (29 + 71)
= 48 * 100
= 4800
1125 - 25 x 30 + 0,06 : 0,2
= 1125 - 750 + 0,3
= 375 + 0,3
= 375,3
GIẢI
91 x 157 - 29 x 91 - 91 x 28
=91 x (157 + 29 + 91)
=91 x 277
=25207
127 x 63 + 19 x 127 - 82 x 26
= 127 x (63 +19) - 2132
= 127 x 92 - 2132
= 11684 - 2132
= 9552
29 x 17 + 31 x 29 + 48 x 93 - 48 x 22
=29 x(17 +31) + 48 x(93 - 22)
=29 x 48 + 48 x71
=48 x (29 + 71)
=48 x 100
=4800
1125 - 25 x 30 + 0,06 : 0,2
= 1100 x 30 + 0,3
= 33000 +0,3
= 33000,3
K HỘ MIK NGHEN
Tính một cách hợp lí :
a) (29 -9 ) . (-9) + (-13 - 7) . 21
b) (-157) . (127 - 316) - 127 . (316 - 157)
a, \(\left(29-9\right).\left(-9\right)+\left(-13-7\right).21\)
\(=20.\left(-9\right)+\left(-20\right).21\)
\(=-180+\left(-420\right)\)
\(=-600\)
Tính một cách hợp lí :
a) (29 - 9) . (-9) + (-13 - 7) . 21
b) (-157) . (127 - 316) - 127 . (316 - 157)
a) (29 – 9). (-9) + (-13 – 7). 21
= 20. (-9) + [- (13 + 7). 21]
= 20. (-9) + (-20). 21
= (-20). 9 + (-20). 21
= (-20). (9 + 21)
= (-20). 30
= - (20. 30)
= - 600.
b) (-157). (127 – 316) – 127. (316 – 157)
= (- 157). 127 + (-157). (-316) + (–127). 316 + (-127). (-157)
= -157. 127 + 157. 316 – 127. 316 + 127. 157
= [- (127. 157) + 127. 157] + (157. 316 – 127. 316)
= 0 + 316. (157 – 127)
= 316. 30
= 9 480.
29.(-130)+27.(29)+(-14).(-29)
giang cho mk voi nha
