[(x+2)(x+5)][(x+3)(x+4)] -24

= (x²+7x+10)(x²+7x+12) -24

=(x²+7x+11-1)(x²+7x+11+1) -24

=(x²+7x+11)²-1-24

=(x²+7x+11)² -25

=(x²+7x+11-5)(x²+7x+11+5)=(x²+7x+6)(x²+7x+16)

✽

mày tự ấn máy tính đi 

đầu tiên là 1248

tiếp theo là 234 nhé

chúc bạn thành công

\(A=1^5+2^5+3^5+......+100^5\)

Ta luôn có \(a^n+b^n=\left(a+b\right)\left(.....\right)\)   \(\text{∀}\) \(n\) ∈ \(N\) , \(n:\) \(lẻ\)

\(A=\left(1^5+99^5\right)+\left(2^5+98^5\right)+.....+\left(49^5+51^5\right)+100^5+50^5\)

\(A=\left(99+1\right)\left(...\right)+\left(2+98\right)\left(....\right)+....+\left(49+51\right)\left(....\right)+100^5+50^5\)

\(A=100\left(...\right)+\left(40+10\right)^5\)

\(Đặt\) \(P=\left(40+10\right)^5=40^5+10^5+5.40^4.10+10.40^3.10^2+10.40^2.10^3+5.40.10^4+10^5\)

Dễ thấy \(P\) ⋮ 4 \(=>A\) ⋮ 4 \(=>\) đpcm

1 + 1 = 2

1 + 2 = 3

HT

ủa cái câu này hỏi tui được mà Q( em gái của tui nha mọi người )

tự tính đê

a)\(\dfrac{1}{Rtđ}=\dfrac{1}{R1}+\dfrac{1}{R2}=\dfrac{1}{8}+\dfrac{1}{12}=\dfrac{5}{24}\)

\(\Rightarrow Rtđ=\)4,8

b)ta có:U=U1+U2=I.Rtđ=3.4,8=14,4

c)I1=\(\dfrac{U1}{R1}=\dfrac{14,4}{8}\)=1,8

I2=I-I1=3-1,8=1,2

Bạn chụp rõ nét đc ko ạ, mik đang ko có kính ở đây

VII

1 It causes ill health in human beings (and lung diseases).

2 Doctors

3 Yes, because the gases from the exhausts of cars have increased air pollution in most cities

4 They cannot think as quickly as other children and are clumsy when they use their hands.

1 The English speaking countries exhibition will last until 8 p.m.

2 How long will the presentation last?

1 The tickets will be collected by Mr. Smith.

2 The picture was painted by a local artist.

3 A book is being read by him.

4 These exercises should be done carefully by Nam.