7 × 3 mu x + 20 × 3 mu x = 3 mu 25

ta có : (ghi lại đề)

=6+12+18+24+30/3+6+9+12+15

=2*(3/3+6/6+9/9+12/12+15/15)

=2*(1+1+1+1+1)

=2*5=10

chúc main học tốt nhé

hi

5^4*20^4/25^5*45=5^4 *5^4*4^4/25^4*25*45=4^4/25*45=256/1125

1048576

1048576

\(\frac{5^4.20^4}{25^5.4^5}=\frac{5^4.\left(2^2.5\right)^4}{\left(5^2\right)^5.\left(2^2\right)^5}=\frac{5^4.2^8.5^4}{5^{10}.2^{10}}=\frac{5^8.2^8}{5^{10}.2^{10}}=\frac{1}{5^2.2^2}=\frac{1}{25.4}=\frac{1}{100}\)

a. =[(-4)(-25)].3=100.3=300

b. =[(-8).125][5.2]=-1000.10=-10000

c. =[25.(-4)][(-5).20]=-100(-100)=10000

bủh

a) 8 × 5 × 9 = (8 × 5) × 9 = 40 × 9 = 360

b) 6 × 7 × 5 = (6 × 5) × 7= 30 × 7= 210

c) 6 × 4 × 25 = 6 × (4 × 25) = 6 × 100= 600

=> 4.(5-5) = 5.(5-5)

=> 4.0=5.0

Bạn đánh lừa người đọc làm người đọc tưởng chừng là nhân 1.Mình cũng bị

vì 5-5=0 các số nào nhân với 0 đều bằng 0

4=5 khi hiệu hoặc tổng = 0

Vì 20-20=0

và 25-25=0

=> 20-20=25-25

=> 4.5-4.5=5.5-5.5

=> 4=5

a: \(\dfrac{8^{20}+4^{20}}{4^{25}+64^5}=\dfrac{2^{60}+2^{40}}{2^{50}+2^{30}}=\dfrac{2^{40}\left(2^{20}+1\right)}{2^{30}\left(2^{20}+1\right)}=2^{10}\)

b: \(\dfrac{45^{10}\cdot5^{20}}{75^{15}}=\dfrac{5^{30}\cdot3^{20}}{3^{15}\cdot5^{30}}=3^5\)

a)\(\dfrac{8^{20}+4^{20}}{4^{25}+64^5}=\dfrac{2^{60}+2^{40}}{2^{50}+2^{30}}=\dfrac{2^{40}\left(2^{20}+1\right)}{2^{30}\left(2^{20}+1\right)}=2^{10}=1024\)

b)\(\dfrac{45^{10}\cdot5^{20}}{75^{15}}=\dfrac{9^{10}\cdot5^{30}}{3^{15}\cdot5^{30}}=\dfrac{3^{20}}{3^{15}}=3^5=243\)

a) 14/15

b) 1/20

c) 4/7

d) 49/50

\(a\) \(\dfrac{3}{5}+\dfrac{1}{3}=\dfrac{9}{15}+\dfrac{5}{15}=\dfrac{14}{15}\)

\(b\) \(\dfrac{17}{20}-\dfrac{4}{5}=\dfrac{17}{20}-\dfrac{16}{20}-\dfrac{1}{20}\)

\(c\) \(\dfrac{25}{35}\times\dfrac{4}{5}=\dfrac{5}{7}\times\dfrac{4}{5}=\dfrac{4}{7}\)

\(d\) \(\dfrac{7}{15}:\dfrac{6}{7}=\dfrac{7}{15}\times\dfrac{7}{6}=\dfrac{49}{90}\)

a. 14/15

b. 1/20

c. 4/7

d. 49/90