Ta có : \(2^{70}=\left(2^7\right)^{10}=128^{10}\)

          \(3^{51}>3^{50}=\left(3^5\right)^{10}=243^{10}\)

Mà :  \(128^{10}< 243^{10}\)\(\rightarrow2^{70}< 3^{50}< 3^{51}\)

        \(\rightarrow2^{70}< 3^{51}\)

Chúc bạn hk tốt 

Ta có:

2^70=(2^7)^10=128^10

3^51=3^50.3=(3^5)^10.3=243^10.3

Vì 128^10<243^10.3<=>2^70<3^51

Vậy 2^70 < 3^51

T*** mik nhé!

Bài 2 : Tính nhanh
16 x 48 + 8 x 48 + 16 x 28 
= 16 x 48 + 8 x 2 x 24 + 16 x 28 
= 16 x 48 + 16 x 24 + 16 x 28 
= 16 x ( 48 + 24 + 28) 
= 16 x 100 
= 1600
Tick mình nha

4590:(x-24+14)=30

x-24+14=4590:30

x-24+14=153

x-24=153-14

x-24=139

x=139+24

x=16

16x48+8x48+16x28

=16x48+16x24+16x28

=16x(48+24+28)

=16x100

=1600

tick mình nha

1) ta có: \(x:3=y.15\Rightarrow x\cdot\frac{1}{3}=y.15\Rightarrow\frac{x}{15}=\frac{y}{\frac{1}{3}}\)

ADTCDTSBN

...

2) bn ghi thiếu đề r

3) ta có: \(3x=7y\Rightarrow\frac{x}{7}=\frac{y}{3}=k\Rightarrow\hept{\begin{cases}x=7k\\y=3k\end{cases}}\)

mà xy = 189 => 7k.3k = 189

                          21 k² = 189

                                 k² = 9 = 3² = (-3)² => k = 3 hoặc k  = - 3

TH1: k = 3

x = 7.3 => x  = 21

y = 3.3 => y = 9

...

4) ta có: \(4x=5y\Rightarrow\frac{x}{5}=\frac{y}{4}\Rightarrow\frac{x^2}{25}=\frac{y^2}{16}\)

ADTCDTSBN

...

b: \(=\dfrac{x+5+x+x-5}{x\left(x+5\right)}=\dfrac{3x}{x\left(x+5\right)}=\dfrac{3}{x+5}\)

\(a,=-3x^3+x^2+9x^2-3x-12x+4=-3x^3+10x^2-15x+4\\ b,=\dfrac{x+5+x+x-5}{x\left(x+5\right)}=\dfrac{3x}{x\left(x+5\right)}=\dfrac{3}{x+5}\)

1, What do you usually prepare for Tet?
I usually prepare new clothes, and fruit, help my parents with work,...

2, What is your favorite festival?
Lion Dance Festival