\(a,\Leftrightarrow72+x=216-48=168\\ \Leftrightarrow x=168-72=96\\ b,BC\left(24,15\right)=B\left(120\right)=\left\{0;120;240;360;480;...\right\}\\ \Leftrightarrow x=240\)

= =8/5

Ta có: \(-\frac{72}{45}=\frac{-72:9}{45:9}=\frac{-8}{5}\)

Lời giải chi tiết:

mông to ko bạn

Bài làm

a) 15 x 18 

= 15 x 2 x 9

= 30 x 9 

= 27

b) 25 × 24

= 25 x 4 x 6

= 100 x 6 

= 600

c) 125 × 72

= 125 x 8 x 9 

= 1000 x 9

= 9000

d) 55 × 14

= 5 x 11 x 2 x 7

= ( 5 x 2 ) x ( 11 x 7 )

= 10 x 77

= 770

# Học tốt #

15 x 18 = 270

25 x 24 = 600

125 x 72 = 9000

55 x 14 = 770

a: \(2004^2-16\)

\(=\left(2004-4\right)\left(2004+4\right)=2000\cdot2008=4016000\)

b: \(892^2+892\cdot216+108^2\)

\(=892^2+2\cdot892\cdot108+108^2\)

\(=\left(892+108\right)^2=1000^2=1000000\)

c: \(36^2+26^2-52\cdot36\)

\(=36^2-2\cdot36\cdot26+26^2\)

\(=\left(36-26\right)^2=10^2=100\)

d: \(\left(10,2\cdot9,8-9,8\cdot0,2\right)+\left(10,22-10,2\cdot0,2\right)\)

\(=9,8\left(10,2-0,2\right)+10,22-2,04\)

=98+8,18

=106,18

e: \(20,03\cdot45+20,03\cdot47+20,03\cdot8\)

\(=20,03\cdot\left(45+47+8\right)\)

\(=20,03\cdot100=2003\)

g: \(15,75\cdot175-15,75\cdot55-15,75\cdot20\)

\(=15,75\cdot\left(175-55-20\right)\)

\(=15,75\cdot100=1575\)

h: \(A=57^2+114\cdot43+43^2\)

\(=57^2+2\cdot57\cdot43+43^2\)

\(=\left(57+43\right)^2=100^2=10000\)

i: \(B=5^4\cdot3^4-\left(15^2-1\right)\left(15^2+1\right)\)

\(=15^4-\left(15^4-1\right)=1\)

k: \(C=50^2-49^2+48^2-47^2+\cdots+2^2-1^2\)

\(=\left(50-49\right)\left(50+49\right)+\left(48-47\right)\left(48+47\right)+\cdots+\left(2-1\right)\left(2+1\right)\)

=50+49+...+2+1

\(=50\cdot\frac{51}{2}=25\cdot51=1225\)

Giúp e vs e cần gấp ạ🥺

a: \(2004^2-16=2000\cdot2008=4016000\)

b: \(892^2+892\cdot216+108^2=1000^2=1000000\)

c: \(36^2-52\cdot36+26^2=10^2=100\)