Bài 1. Thực hiện phép tính (tính hợp lý nếu có thể):
d) (12 + 22 + ...... + 1002). (34 - 92)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) (-124) + 24 = -100
b) 37. 78 + 37. 22
= 37 . ( 78 + 22 )
= 37 . 100
= 3700
a, (-20) + 16 + (-34) + 20 = [(-20) + 20] + [16 + (-34)] = 0 + (-18) = (-18) b, 12 + 3.[39 - (5 - 2)2] = 12 + 3.[39 - 32] = 12 + 3.[39 - 9] = 12 + 3.30 = 12 + 90 = 102
e: =5/7(5/11+2/11-14/11)
=5/7(-7/11)=-5/11
f: =-5/4(2/11+9/11)+1+3/4
=-5/4+7/4
=2/4=1/2
g: =-5/7(3/13+10/13)+1+5/7
=-5/7+1+5/7
=1
h: =7/4(29/5-9/5)+41/13
=-7+41/13=-50/13
BÀi 1:
a: (-243+345)-(257+(-55)-129)
=-243+345-257+55+129
=(-243-257)+(345+55)+129
=-500+400+129
=-100+129
=29
b: \(\left(-2\right)^3-45:\left(-3\right)^2-\left(-2019\right)^0\cdot\left(-1\right)^{2019}\)
\(=-8-\frac{45}{9}-1\cdot\left(-1\right)\)
=-8-5+1
=-13+1
=-12
c: \(\left\lbrack27\cdot\left(-67\right)+33\cdot\left(-27\right)\right\rbrack:\left(-30\right)\)
\(=\frac{-27\left(67+33\right)}{-30}\)
\(=\frac{9}{10}\cdot100=90\)
d: \(\left(1^2+2^2+\cdots+100^2\right)\left(3^4-9^2\right)\)
\(=\left(1^2+2^2+\cdots+100^2\right)\left(81-81\right)\)
=0
e: \(53\cdot47+53^2-2021^0\)
\(=53\left(53+47\right)-1\)
=5300-1
=5299
i: 38+(-21)+(-58)+(-6)
=(38-58)+(-21-6)
=-20-27
=-47
h: (2020+27)-[2020+(-73)]-129
=2020+27-2020+73-129
=100-129
=-29
a) 23.125+78.125-125
= (23+78-1).125
= 100.125
= 12500
b) 37.46+18.54-17.46+54.2
= (37-17).46+(18+2).54
= 20.46+20.54
= 20.(46+54)
= 20.100
= 2000
c) 3.22-23:2+22
= 3.22-22+22
= 3.22
= 3.4
= 12
d) 73.9+32.74-45.539
= 73.9+9.74-5.9.72.11
= 9.(73+74)-5.9.72.11
=9.2744-9.2695
= 9.(2744-2695)
= 9.49
= 441
a/
=125(23+78-1)=125.100=12500
b/
=46(37-17)+54(18+2)
=20(46+54)=20.100=2000
c/
=3.22-22+22=3.4=12
d/
=73.32+32.74-5.32.72.11=
=32.72(7+72-55)=32.72=441
d) Ta có: \(-8+\left(-14\right)+34+\left(-12\right)\)
\(=-8-14+34-12\)
\(=-20+20\)
\(=-0\)
e) Ta có: \(\left(-7\right)+\left(-20\right)+57+\left(-30\right)\)
\(=\left(-7+57\right)+\left(-20-30\right)\)
\(=50-50=0\)
f) Ta có: \(300-\left(-180\right)-120-42\)
\(=300+180-120-42\)
\(=258+60=318\)
d, Ta có : \(\left(-8\right)+\left(-14\right)+34+\left(-12\right)\)
\(=-\left(8+12\right)+34-14=-20+20=0\)
e, Ta có : \(\left(-7\right)+\left(-20\right)+57+\left(-30\right)\)
\(=-\left(30+20\right)+57-7=-50+50=0\)
f, Ta có : \(300-\left(-180\right)-120-42=318\)
\(34\times76+66\times110+34\times34\)
\(=34\times\left(76+34\right)+66\times110\)
\(=34\times110+66\times110=110\times\left(34+66\right)=110\times100=110000\)
34 x 76 + 66 x 110 + 34 x 34
= 34 x ( 76 + 34 ) + 66 x 110
= 34 x 110 + 66 x 110
= 110 x ( 34 + 66 )
= 110 x 100
= 11 000
=))
\(=\left(1^2+2^2+...+100^2\right)\cdot0=0\)