7.50+9.[(-3)-(-27)]
=350+9.24
=350+216
=566
k minh nhe ban
7 . 50 + 9 . ( - 3 - 27 )
= 7 . 50 + 9 . ( - 30 )
= 350 + ( - 270 )
= 80
TINH:
7.50+9.((-3)-(-27))
\(\dfrac{-1}{3}.\dfrac{2}{5}\)
\(\dfrac{-3}{7}.\dfrac{4}{15}\)
\(\dfrac{-9}{3}.\dfrac{15}{27}\)
\(\dfrac{-5}{6}.\)( -12 )
\(\dfrac{-12}{4}.\dfrac{8}{9}\)
\(-3.\dfrac{7}{6}\)
\(\dfrac{-15}{9}.\dfrac{27}{5}\)
\(-9.\dfrac{4}{27}\)
Tính một cách hợp lí
a) (−27). 1011 − 27. (−12) + 27. (−1) b) (−9). (−9). (−9) + 103 + 9
3
c) (−157). (127 − 316) − 127. (316 − 157) éc o éc
Tính một cách hợp lí
a) (−27). 1011 − 27. (−12) + 27. (−1) b) (−9). (−9). (−9) + 103 + 9
3
c) (−157). (127 − 316) − 127. (316 − 157) giúp mik ik các cậu ơi
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
a) 2^7 . 9^3 / 6^5 . 8^2
b) 6^10 . 27^5 / 4^5 . 81^6
c) 3^18 . 32^9 / 64^7 . 27^6
d) 9^12 . 3^5 + 9^15 / ( 2. 27 )^5 . 3^14
e) 5^4 + 2^2 . 5^2 - 125 / 2^3 . 3
Rút gọn:
a)18^3:9^3
b)27^4.81^10
c)27^8:9^4
d)9^25.27^4.81^3
a. 3/2.(5/7-4/3)-4/3(5/7-3/2)
b. 7/9.(27/35-4/3)-4/3(27/35-7/9)
\(\frac{\frac{27}{3}\times14\times20+\frac{9}{2}\times780\times3}{3+6+9+...+24+27}\)
