7650 : 765 x 85 + 875 - 73 = ???
\(\frac{x-85}{15}+\frac{x-73}{13}+\frac{x-67}{11}+\frac{x-64}{9}=10\)
\(\frac{x-85}{15}+\frac{x-74}{13}+\frac{x-67}{11}+\frac{x-64}{9}=10\\ \Leftrightarrow\left(\frac{x-85}{15}-1\right)+\left(\frac{x-74}{13}-2\right)+\left(\frac{x-67}{11}-3\right)+\left(\frac{x-64}{9}-4\right)=10-10\\ \Leftrightarrow\frac{x-100}{15}+\frac{x-100}{13}+\frac{x-100}{11}+\frac{x-100}{9}=0\\ \Leftrightarrow\left(x-100\right)\left(\frac{1}{15}+\frac{1}{13}+\frac{1}{11}+\frac{1}{9}\right)\Leftrightarrow x-100=0\left(Vi\frac{1}{15}+\frac{1}{13}+\frac{1}{11}+\frac{1}{9}\ne0\right)\Leftrightarrow x=100\)
7650 : 2 = ???
thuc hien phep tinh
73 . 35 + 27 . 19 - 20 . 73 + 81 . 27 + 85 . 73
73 . 35 + 27 . 19 - 20 . 73 + 81 . 27 + 85 . 73
= 73 . ( 35 - 20 + 85 ) + 27. ( 19 + 81 )
= 73 . 100 + 27. 100
= ( 73 + 27 ) . 100
= 100 . 100
= 10 000
73. 35+ 27.19- 20. 73+ 81. 27+ 85. 73
= 73.(35+ 85 - 20) + 27.(19+81)
=73.100 +27.100
=100.(27+73)
=100.100
=10000
Tick mìn nha
hãy so sánh:67 phần 77 và 73 phần 83
B:456 phần 461 và 123 phần 128
C:64 phần 85 và 73 phần 128
D 64 phần 85 và 73 phần 81
Tính (-48)+127+(-52)+73 (-38)x45+(-38)x55 (-125)+371+(-875)+629+150 271+(-392)+729+(-608+(-123) (-48)x25+25x(-52) 47x(-11)+47 56-7x8+11 -42+51+2+(-11)+40
a) \(\left(-48\right)+127+\left(-52\right)+73\)
\(=\left(-48-52\right)+\left(127+73\right)\)
\(=-100+200\)
\(=100\)
b) \(\left(-38\right)\cdot45+\left(-38\right)\cdot55\)
\(=\left(-38\right)\cdot\left(45+55\right)\)
\(=\left(-38\right)\cdot100\)
\(=-3800\)
c) \(\left(-125\right)+371+\left(-875\right)+629+150\)
\(=\left(-125-875\right)+\left(371+629\right)+150\)
\(=-1000+1000+150\)
\(=150\)
d) \(271+\left(-392\right)+729+\left(-608\right)+\left(-123\right)\)
\(=\left(271+729\right)+\left(-392-608\right)-123\)
\(=1000-1000-123\)
\(=-123\)
e) \(\left(-48\right)\cdot25+25\cdot\left(-52\right)\)
\(=25\cdot\left(-48-52\right)\)
\(=25\cdot-100\)
\(=-2500\)
f) \(47\cdot\left(-11\right)+47\)
\(=47\cdot\left(-11+1\right)\)
\(=47\cdot-10\)
\(=-470\)
g) \(56-7\cdot8+11\)
\(=56-56+11\)
\(=0+11\)
\(=11\)
h) \(-42+51+2+\left(-11\right)+40\)
\(=\left(-42+2\right)+\left(51-11\right)+40\)
\(=-40+40+40\)
\(=0+40\)
\(=40\)
a: =-48-52+127+73
=200-100
=100
b; \(=-38\left(45+55\right)=-38\cdot100=-3800\)
c: \(=-125-875+371+629+150\)
=-1000+1000+150
=150
d: =271+729-392-608-123
=1000-1000-123
=-123
e: =25(-48-52)
=25*(-100)
=-2500
f: =47(-11+1)
=47(-10)
=-470
g: =56-56+11
=11
h: =-42+2+51-11+40
=-40+40+40
=40
7650 : 2 và chia 5 = ???
nghĩa mik đang bảo là
7650 : 2 và 7650 : 5 nhá
765 x 123 - 765 x 23
=765 x(123-23)
=765 x 100
=76500
=763x(123-23)
=763x100
=76300
nhớ k đúng nha
765*123-765*23
=765*(123-23)
=765*100
=76500
Tính bằng cách thuận tiện: 765 x 45 + 50 x 765 + 765 x 4 + 765
=765x(45+50+5)
=765x100
=76500
Bài 1 Tính hợp lý :
a) 2020-( 249+ 2020) +( 249 - 573)
b) |- 257| + (-3)° - (18+ 257)
c) 25( 85- 47) -85(47+25)
d) 39. 73- 73( - 61)
Bài 2 : Tìm số nguyên x biết : a) 15-5(x+2) = -30
b) (x+2)mũ 2 + 5 = 105
c) |2x-5| -(-6) = 11
d) 3x - 5 chia hết cho x +2
e) 3x +7chia hết cho 2x +1
1,
a,\(2020-\left(249+2020\right)+\left(249-573\right)\)
\(=2020-249-2020+249-573\)
\(=-573\)
b,\(\left|-257\right|+\left(-3\right)^0-\left(18+257\right)\)
\(=257+1-18-257\)
\(=1-18=-17\)
\(c,25.\left(85-47\right)-85.\left(47+25\right)\)
\(=25.85-25.47-47.85+85.25\)
\(=85.\left(25-47+25\right)-25.47\)
\(=85.3-25.47\)
\(=-920\)
2,
\(a,15-5.\left(x+2\right)=-30\)
\(=>5.\left(x+2\right)=15+30=45\)
\(=>x+2=\frac{45}{5}=9\)
\(=>x=7\)
\(b,\left(x+2\right)^2+5=105\)
\(=>\left(x+2\right)^2=100\)
\(=>\left(x+2\right)^2=10^2\)
\(=>x+2=10\)
\(=>x=8\)
\(c,\left|2x-5\right|-\left(-6\right)=11\)
\(=>\left|2x-5\right|=11-6=5\)
\(=>\orbr{\begin{cases}2x-5=5\\2x-5=-5\end{cases}}\)
\(=>\orbr{\begin{cases}2x=5-5=0\\2x=-5+5=0\end{cases}=>x=0}\)