Đáp án:
Giải thích các bước giải:
a) (2x^2+3)^2
=(2x²)² +2x².2 .3 +3²
=4x^4 +12x² +9
b) (y^2x-3ab)^2
=(y^2x)² -2.3ab .y^2x +(3ab)²
=y^4x -6aby^2x +9a²b²
c) (x^2-6z) . (x^2 +6z)
=(x²)² -(6z)²
=x^4 -36z²
$\ a)$ $\ (2x²+3)²$
$\ = (2x²)² +2x².2 .3 +3²$
$\ =$ $4x^{4}$ $\ +12x² + 9$
$\ b)$ $\ ($ $y^{2x}$ $\ -3ab)²$
$\ =$ $\ ($ $y^{2x}$ $\ )$ $\ ²$ $\ -2.3ab .$ $y^{2x}$ $\ + (3ab)²$
$\ =$ $y^{4x}$ $-6aby^{2x}$ $\ + 9a²b²$
$\ c)$ $\ ($ $x^{2-6z}$ $\ )$ $\ . ($ $x^{2+6z}$ $\ )$
$\ = ($ $x^{2}$ $\ )²$ $\ -($ $6z)^{2}$
$\ =$ $x^{4}$ $\ -36z²$
I Find the word which has a different sound in the underlined part. 1. A. unit B. use C. university D. unchanged 2. A. ache B. charity C. charming D. changeful 3. A. whole B. whereas C. whose D. whom 4. A. slaughter B. laughter C. naughty D. taught 5. A. service B. office C. device D. practice X Read the passage. Life is changing rapidly in the large cities of England. However, life in other areas remains much the (1) ……………………… as it has been for centuries. Factories have brought huge population increases to the cities, and city life boomed. City residents have discovered a new (2) ……………………… of life, but in country villages the traditional lifestyle has remained nearly (3) ………………… There have been a few changes, particularly the new steam-powered machinery. It made farm production more (4) …………………… But for the people who remain in the countryside, daily life continues much as it had before the (5) …………………… Revolution. Life in country villages continues to (6) ……………… at a slow pace. The daily schedule depends on the times that the sun rose and set and on the weather. In a typical village, the (7) ……………… number of workers is still employed in agriculture or in domestic service. A smaller number of people work in various trades. Even (8) ……………………… work in the professions. XChoose the most suitable word to fill in the blank 1. A. similar B. same C. different D. both A & B 2. A. method B. walk C. way D. path 3. A. changeful B. changeable C. unchanged D. change 4. A. efficient B. efficiently C. efficiency D. inefficient 5. A. Industry B. Industrial C. Industrialize D. Industrialized 6. A. run B. walk C. move D. drive 7. A. largest B. biggest C. highest D. all are correct 8. A. more B. less C. few D. fewer Fill in the blank with one word/ phrase from the passage 1. The population in the city has increased because of ……………… . 2. There has been hardly any changes in the ……………… in rural areas. 3. Steam – powered machinery helps ……………… a lot. 4. The daily schedule of people in the countryside depends on ……………… . 5. Most countryside people in England work in agriculture or in ………………
fill each gap of the following sentences with a suitable preposition 1. THEY often play catch ...................... recess 2. We could go ..........................the trip because we could afford if 3.I haven't been able to concentrate recently..........................work.I don't know what it is 4. They place could't take.........................at 11 o'clock after the fog had lifter 5. My grandfather was able to walk help last night
vẽ con ma hơi cute chứ ko cute quá
Mng giúp em giải mây câu hình này bằng phương pháp toạ độ với ạ
viết thơ về chính bản thân b đi??????????????????????????????????????????????????????????????????????????
tìm x bt : x^3+(x-1)^3=(2x-1)^3-6x^3
ở cùng nỗi buồn trọn ngày :) xD [27.08.20-28.08-20] vẽ anime buồn ... không mạng, cap 2 ảnh hen (có và không có chữ kí) x@u = bay màu ._? không nhận ảnh cũ
Giải giúp mình bài 2,3 phần c bài 2 k lam cx đc
xác định nồng độ mol của các dung dịch trong các trừong hợp sau a. hòa tan 240g SO3 vào nước sau phản ứng tìm được dung dịch có thể tích 2lít b. hòa tan 31.36 lít khí HCL(dktc) vào nước thu dc 0.5 lít dung dịch c. hòa tan 100g ZnSO5 vào 400g nước thu được một dung dịch có khối lượng riêng D=1,232g/ml
2[( 95 + 5mũ202:5mũ201) : 2mũ2+2mũ3.3mũ2.5] - 2mũ2 . 10mũ2
Loga.vn - Cộng Đồng Luyện Thi Trực Tuyến
