1 / 9 = x / 27
Ta có :
9 * x = 27
x = 27 / 9
x = 3
Vậy x = 3
1 / 9 = x / 27
Ta có :
9 * x = 27
x = 27 / 9
x = 3
Vậy x = 3
câu 3
ta có \(\frac{x}{-3}\)=y/5 => x=\(\frac{-3y}{5}\)
thay x= -3y/5 vào xy=-5/27 ta được
-\(\frac{-3y}{5}\)*y=-5/27
=>\(\frac{-3y^{^2}}{5}\)=-5/27
=>.-3y^2 =-5/27 :5=-5/27*1/5
=> -3y^2=-1/27
=>y^2 =-1/27 :(-3)=-1/27*(-1/3)=1/81
=>y=1/9
Khi đó x= -5/27 : 1/9 = -5/27 *9 = -5/3
vậy x= -5/3 ,y = 1/9
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
Tính:
a) 2^5 x 13^12 x 7^8 : 27 x 13^10 x 7^9
b) 2^n x 11 x 3 : 6^n x 3
c) 5^5 x 7 x 9^5 : 15^10
d) 7 x 8^10 x 27^9 - 8 x 9^13 x 2^27 : 7 x 6^26 x 2^2 - 2^4 x 8^3 x 27^9
e) 2^2^1^2015
f) 2015^0^2015^0^2015
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
c/ 1/9=x/27
Câu 15: Tìm x thuộc bội của 9 và x < 63
A. x ∈ {0; 9; 18; 27; 36; 45; 54} B. x ∈ {0; 9; 18; 28; 35}
C. x ∈ {9; 18; 27; 36; 45; 54; 63} D. x ∈ {9; 18; 27; 36; 45; 55; 63}
tìm x (simple)
1/27=(1/9)^x
(4.x-1) mũ 12 = 27 nhân (4.x -1) mũ 9
1) 27,56 x 35 + 27,56 x67- 27,56 x2
2) 4 x 35 x 25 x 5 x2
3) ( 32 x 18 - 16 x 36 ) x( 1+3+5+7+......+1001)
4) 3/5 + 2/5 x 1/2 - 2/3 x 3/4
5) 27 x 13 + 35 x 27 - 12 x 9
6) 33/5 x 15/11 + 22/27 x 81/44 - 3/5 : 9/5