a: (-14)+(-16)+24

=-14-16+24

=-30+24

=-6

b: |-25|x71+29x25

\(=25\cdot71+25\cdot29\)

\(=25\left(71+29\right)=25\cdot100=2500\)

c: \(=132:\left(41+28-5^2\right)\)

\(=132:\left(69-25\right)=132:44=3\)

Đáp án:

 a, 38+41+117+159+6238+41+117+159+62

=(38+62)+(41+159)+117=(38+62)+(41+159)+117

=100     +200      +117=100     +200      +117

=417=417

b, 73+86+968+914+303273+86+968+914+3032

=73+(86+914)+(968+3032)=73+(86+914)+(968+3032)

=73+1000     +4000=73+1000     +4000

=5073=5073

c, 341.67+341.16+659.83341.67+341.16+659.83

=341.(67+16)+659.83=341.(67+16)+659.83

=341.83+659.83=341.83+659.83

=83.(341+659)=83.(341+659)

=83.1000=83000=83.1000=83000

d, 42.53+47.156−47.11442.53+47.156-47.114

=42.53+47.(156−114)=42.53+47.(156-114)

=42.53 +47.42=42.53 +47.42

=42.(53+47)=42.100=42.(53+47)=42.100

=4200=4200

e, 563.23+23.26+23563.23+23.26+23

=23.(563+26+1)=23.(563+26+1)

=23.600=23.600

=13800=13800

f, 132+157+43+68132+157+43+68

=(132+68)+(157+43)=(132+68)+(157+43)

=200      +200=400=200      +200=400

g, 49.68+100.34+6849.68+100.34+68

=49.68+50.68+68=49.68+50.68+68

=68.(49+50+1)=68.(49+50+1)

=68.100=6800=68.100=6800

h, 491.(267+53)+491.(151+67)491.(267+53)+491.(151+67)

=491.(267+53+151+67)=491.(267+53+151+67)

=491.538=491.538

=264158=264158

Vote mk nha.

a) \(38 + 41 + 117 + 159 + 62\) \(= (38 + 62) + (41 + 159) + 117\)
\(= 100 + 200 + 117\)
\(=417\)

b) \(73 + 86 + 968 + 914 + 3032\) \(= 73 + (86 + 914) + (968 + 3032)\)
\(= 73 + 1000 + 4000\)
\(=5073\)

c) \(341 \cdot 67 + 341 \cdot 16 + 659 \cdot 83\) \(= 341 \cdot (67 + 16) + 659 \cdot 83\)
\(= 341 \cdot 83 + 659 \cdot 83\)
\(= (341 + 659) \cdot 83\)
\(= 1000 \cdot 83\)
\(=83000\)

e) \(563 \cdot 23 + 23 \cdot 36 + 23\) \(= 563 \cdot 23 + 23 \cdot 36 + 23 \cdot 1\)
\(= 23 \cdot (563 + 36 + 1)\)
\(= 23 \cdot 600\)
\(=13800\) f) \(132 + 157 + 43 + 68\) \(= (132 + 68) + (157 + 43)\)
\(= 200 + 200\)
\(=400\)

g) \(49 \cdot 68 + 100 \cdot 34 + 68\) \(= 49 \cdot 68 + 50 \cdot 68 + 1 \cdot 68\) (vì \(100 \cdot 34 = 50 \cdot 68\))
\(= (49 + 50 + 1) \cdot 68\)
\(= 100 \cdot 68\)
\(=6800\)

bằng 1/3 bạn nhé ..check mk đó.

\(\left(\frac{1}{3}+\frac{12}{67}+\frac{13}{41}\right)-\left(\frac{79}{67}-\frac{28}{41}\right)\)

\(=\frac{1}{3}+\frac{12}{67}+\frac{13}{41}-\frac{79}{67}+\frac{28}{41}\)

\(=\left(\frac{12}{67}-\frac{79}{67}\right)+\left(\frac{13}{41}+\frac{28}{41}\right)+\frac{1}{3}\)

\(=\left(-1\right)+1+\frac{1}{3}\)

\(=\frac{1}{3}\)

a)123-4x=8+67

123-4x=75

4x=123-75

4x=48

x=48:4

x=12

b)4.|x|-25=3⁹:3⁸

4.|x|-25=3¹(=3)

4.|x|=3+25

4.|x|=28

|x|=28:4

|x|=7

TH1: TH2:

x=7 x=-7

vậy x E(dấu thuộc nha) (7;-7)

2/15-2/65-4/39=4/39-4/39=0

32/13-(7/23+8/23)=32/13-15/23=541/299

(1/3+12/67+13/41) - (79/67 - 28/41)=6836/8241-1363/2747=1/3

38/145 - (8/45-17/51-3/11)=38/145-(-212/495)=1982/2871

4³⁹ + 4⁴⁰ + 4⁴¹ = 4³⁸ . 4 + 4³⁸ . 4² + 4³⁸ .4³ = 4³⁸ (4+16+64) = 84 . 4³⁸ => chia hết cho 28