Đáp án: `S={4;\frac{2}{3}}`
Giải thích các bước giải:
$(2x+3)(x-4)=(x-5)(4-x)$
$⇔2x^2-5x-12=-x^2+9x-20$
$⇔3x^2-14x+8=0$
$⇔3x^2-12x-2x+8=0$
$⇔3x(x-4)-2(x-4)=0$
$⇔(x-4)(3x-2)=0$
$⇔\left[ \begin{array}{l}x-4=0\\3x-2=0\end{array} \right.⇔\left[ \begin{array}{l}x=4\\x=\frac{2}{3}\end{array} \right.$
(2x^3+3)(x-4)=(x-5)(4-x)
2x^4-8x^3+3x-12=4x-x^2-20+5x
2x^4-8x^3+3x-4x+x^2-5x=-20+12
4x^4-8x^3+x^2-6x = -8
11. I.......his car to work while he was sleeping. A. drive B. drove C. driving D. driven
bài 2 bỏ ngoặc rồi tính a,(27 + 514)-(486 - 73) b,(36 + 79)+(145 - 79 - 36) c, 10 -[12-(- 9 - 1 )] d,(38 - 29 + 43)-(43 + 38) e, 271 - [(-43)+271 -(-17)] g,-144 -[29-(+144)-(+144)]
Theo em, dân ta có giữ được những phong tục tập quán của tổ tiên ko?
Cho bất phương trình 2x+3y-2 <0 . Miền nghiệm của bất phương trình?
Cho tam giác ABC vuông tại B(AC>AB).D là điểm thuộc AC sao cho AB=AD.Kẻ AH vuông góc với BD tại H, AH cắt BC tại E. a,CMR tam giác ABH =tam giác ADH b,CMR EBD là ∆cân c,Giả sử BED=120°,AB=2cm.Tính BC giúp với mình cần gấp
IV. Chia dạng đúng của từ trong ngoặc. (2 điểm) 1.He is a famous stamp ___________(COLLECT) 2.There was some new ___________in the laboratory. (EQUIP) 3.It was an ___________day. (ENJOY) 4.The accident happens because of driving ___________ (CARE) 5.Some young people today have a very strange ___________(APPEAR) 6.Her clothes look very modern and ___________ (FASHION) 7.Many designers took ___________from Vietnam’s ethnic minorities. (INSPIRE) 8.His attempt to break the world record was sadly ___________(SUCCESS)
Giúp mình vs Cảm ơn trước nha ❤️❤️❤️
Giúp mình với mình cần gấp . Câu 16 và 17 nhé
Các bạn giúp mình với nha mình đang can4 lém ấy
Air pollution is a cause of ill-health in human beings. In a lot of countries there are laws limiting the amount of smoke which factories can produce. Although there isn’t enough information on the effects of smoke in the atmosphere, doctors have proved that air pollution causes lung diseases. The gases from the exhausts of cars have also increased air pollution in most cities. The lead in petrol produces a poisonous gas which often collects in busy streets surrounded by high buildings. Children who live in areas where there is a lot of lead in the atmosphere cannot think as quickly as other children and they are clumsy when they use their hands. There are other long-term effects of pollution. If the gases in the atmosphere continue to increase, the earth’s climate may become warmer. A lot of the ice near the Poles may melt and may cause serious floods. 1. What can make people sick? ___________________________________________________ 2. Where does smoke come from? ___________________________________________________ 3. Can air pollution cause lung diseases? ___________________________________________________ 4. What else can cause air pollution in cities? ___________________________________________________ 5. Why does the earth’s climate become warmer? ___________________________________________________
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