Phần BA là phần nào á b mình zoom ảnh thấy phần C

phần c á bạn, mình nhầm

5A

1B

3C

4D

\(#TyHM\)

1, How far is it from Mr. Pha's house to the market?

2, Where do the Hani people live?

3. What does Minh enjoy?

4. What time did he leave the party?

19.B

20.C

III.

1.goes

2.Do - want

3.is waiting - phones

4.do - never wear 

5.Do - understand

6.will go

7.Do - go out

52/59 nha

a) Đặt \(a=x^2+x\)

Đa thức trở thành: \(a^2-14a+24=\left(a^2-14a+49\right)-25=\left(a-7\right)^2-25=\left(a-7-5\right)\left(a-7+5\right)=\left(a-12\right)\left(a-2\right)\)

Thay a:

\(\left(a-12\right)\left(a-2\right)=\left(x^2+x-12\right)\left(x^2+x-2\right)\)

b) Đặt \(a=x^2+x\)

Đa thức trở thành:

\(\left(x^2+x\right)^2+4x^2+4x-12=\left(x^2+x\right)^2+4\left(x^2+x\right)-12=a^2+4a-12=\left(a^2+4x+4\right)-16=\left(a+2\right)^2-16=\left(a+2-4\right)\left(a+2+4\right)=\left(a-2\right)\left(a+6\right)\)

Thay a:

\(\left(a-2\right)\left(a+6\right)=\left(x^2+x-2\right)\left(x^2+x+6\right)\)

e: \(\left(-4156+2021\right)-\left(119+2021-4156\right)\)

\(=-4156+2021-119-2021+4156\)

\(=\left(-4156+4156\right)+\left(2021-2021\right)-119\)

=0+0-119

=-119

g: \(315\cdot75-\left(15\cdot100-315\cdot25\right)\)

\(=315\cdot75-15\cdot100+315\cdot25\)

\(=315\left(75+25\right)-15\cdot100\)

\(=315\cdot100-15\cdot100=300\cdot100=30000\)

h: \(\left(-489\right)\cdot125-\left(125\cdot11-500\cdot25\right)\)

\(=-489\cdot125-125\cdot11+500\cdot25\)

\(=125\left(-489-11\right)+500\cdot25\)

\(=125\cdot\left(-500\right)+500\cdot25\)

\(=500\left(-125+25\right)\)

\(=500\cdot\left(-100\right)=-50000\)

Bài 2:

a: \(-415-3\left(2x-1\right)^2=-490\)

=>\(3\left(2x-1\right)^2+415=490\)

=>\(3\left(2x-1\right)^2=75\)

=>\(\left(2x-1\right)^2=25\)

=>\(\left[{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)