x+13/34 = 12/14
1. Tính :
a. 12 x 13 + 12 x 49 + 12 x 14 + 14 x 78
b. 34 x 34 + 56 x 45 .
2. Hãy kết bạn với mình -- mình là ARMY nhá
a.1872
b.3676
2 tui cũng là army yiu bts nhìu
----jung hosoek---
a) 12 x 13 + 12 x 49 + 12 x 14 +14 x 78 = 1873
b) 34 x 34 + 56 x 45 = 3676
\(1.\text{ Tính : }\)
\(a,\text{ }12\text{ x }13+12\text{ x }49+12\text{ x }14+14\text{ x }78\)
\(=12\text{ x }\left(13+49\right)+14\text{ x }\left(12+78\right)\)
\(=12\text{ x }62+14\text{ x }90\)
\(=744+1260\)
\(=2004\)
\(b,\text{ }34\text{ x }34+56\text{ x }45\)
\(=1156+2520\)
\(=3676\)
Tìm x biết:
a ) | x | = 1 5 + 3 4 ; b ) | x − 5 | = − − 5 3 + 1 4 ;
c ) x − 1 4 = 3 2 + 1 3 − 7 6 ; d ) x − 4 3 = 1 6 + 5 3 − 1 2 + 7 12 .
a ) x = 19 20 x = 19 20 b ) x = 83 12 x = − 37 12
c ) x = 31 12 x = − 25 12 d ) x = 13 4 x = − 7 12
14 + 12 + 13 + 45 =?
12 + 13 + 34 =?
\(14+12+13+45=84\)
\(12+13+34=59\)
k mk nha o0o Phương Uyên o0o
\(14+12+13+45=84\)
\(12+13+34=59\)
Năn nỉ đó k mình nha!
Tính: a) (43 -13).(-3) +27.(-14 - 16); b) (-72).(34 -12) -34.(12 - 72).
Tìm x, biết
a) x : − 2 1 15 + 3 1 2 = − 3 4 b) − 5 8 − x : 3 5 6 + 7 3 4 = − 2
c) x − 3 4 − 1 4 = 0 d) 3 4 : 2 4 9 − − 3 x + 2 2 3 = 3 4
e) x − 1 3 = 2 − 3 x f) 3 5 7 x − 1 5 7 x − 1 3 = 2 3
g) − 3 4 3 x − 1 = − 27 64 h) 4 5 2 x + 5 = 256 625
i) x − 2 15 3 = 8 125 k) x + 3 5 x + 3 2 = 64 27
m) x − 1 x + 5 = 6 7 n) 4 13 . 6 5 + 4 13 . 2 5 . 2 x + 1 2 = 10 13
Tính hộ mình nha :
Tính:
a) (43 -13).(-3) +27.(-14 - 16)
b) (-72).(34 -12) -34.(12 - 72).
a) (43 -13).(-3) +27.(-14 - 16) = -900
b) (-72).(34 -12) -34.(12 - 72) = 456
Tìm x Biết:
\(\frac{x+32}{11}+\frac{x+33}{12}=\frac{x+34}{13}+\frac{x+35}{14}\)
\(\frac{x+32}{11}+\frac{x+33}{12}=\frac{x+34}{13}+\frac{x+35}{14}\)
\(\Leftrightarrow\left(\frac{x+32}{11}-1\right)+\left(\frac{x+33}{12}-1\right)=\left(\frac{x+34}{13}-1\right)+\left(\frac{x+35}{14}-1\right)\)
\(\Leftrightarrow\frac{x-21}{11}+\frac{x-21}{12}=\frac{x-21}{13}+\frac{x-21}{14}\)
\(\Leftrightarrow\left(x-21\right)\left(\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)=0\)
Vì \(\left(\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)\ne0\)
\(\Rightarrow x-21=0\Rightarrow x=21\)
\(\frac{x+32}{11}+\frac{x+33}{12}=\frac{x+34}{13}+\frac{x+35}{14}\)
\(\Leftrightarrow\left(\frac{x+32}{11}-1\right)+\left(\frac{x+33}{12}-1\right)=\left(\frac{x+34}{13}-1\right)+\left(\frac{x+35}{14}-1\right)\)( trừ cả hai vế cho 2 )
\(\Leftrightarrow\frac{x-21}{11}+\frac{x-21}{12}=\frac{x-21}{13}+\frac{x-21}{14}\)
\(\Leftrightarrow\frac{x-21}{11}+\frac{x-21}{12}-\frac{x-21}{13}-\frac{x-21}{14}=0\)
\(\Leftrightarrow\left(x-21\right)\left(\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)=0\)
Mà \(\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\ne0\)
\(\Rightarrow x-21=0\)
\(\Leftrightarrow x=21\)
Vậy \(x=21\)
Tìm x:
\(\dfrac{x+32}{11}+\dfrac{x+33}{12}=\dfrac{x+34}{13}+\dfrac{x+35}{14}\)
\(\dfrac{x+32}{11}+\dfrac{x+33}{12}=\dfrac{x+34}{13}+\dfrac{x+35}{14}\)
\(\Leftrightarrow\left(\dfrac{x+32}{11}-1\right)+\left(\dfrac{x+33}{12}-1\right)=\left(\dfrac{x+34}{13}-1\right)+\left(\dfrac{x+35}{14}-1\right)\)
\(\Leftrightarrow\dfrac{x+21}{11}+\dfrac{x+21}{12}=\dfrac{x+21}{13}+\dfrac{x+21}{14}\)
\(\Leftrightarrow\dfrac{x+21}{11}+\dfrac{x+21}{12}-\dfrac{x+21}{13}-\dfrac{x+21}{14}=0\)
\(\Leftrightarrow\left(x+21\right)\left(\dfrac{1}{11}+\dfrac{1}{12}-\dfrac{1}{13}-\dfrac{1}{14}\right)=0\)
Mà \(\dfrac{1}{11}+\dfrac{1}{12}-\dfrac{1}{13}-\dfrac{1}{14}\ne0\)
\(\Leftrightarrow x+21=0\)
\(\Leftrightarrow x=-21\)
Vậy ..
tính
a)12+13+14
b)13+70+34
a 12+13+14=25+14=19 b 13+70+34=83+34=117
a 12+13+14=25+14=19 b 13+70+34=83+34=117
a 12+13+14=25+14=19 b 13+70+34=83+34=117
a 12+13+14=25+14=19 b 13+70+34=83+34=117