A = ( 1/1 + 1/2 + 1/3 +...+1/98) x 2 x 3 x 4 Chứng minh A chia hết cho 99 Help me please <3

Anh chị giúp em giải câu 5 vs ạ em cần gấp lắm ạ

a)2x+1/2x-1-2x-1/2x+1=8/4x^2-1 b)3/2x-16+3x-20/x-8+1/8=13x-102/3x-24 c)6/x^2-1+5=8x-1/4x+4-12x-1/4-4x d)1/x+3+8/(x+1)(x-3)=x+3/x^2-2x-3

Vẽ hộ cái tháp rùa , vẽ cả bóng dưới nước luôn trong tranh nha mn :>>

1.Those....children have many problems and they really need our help (advantage) 2.There are more and more youngsters who are......in doing volunteer work (interest) 3.I got some.....advise from my teacher .It was really helpful (use) 4.The ..... rate has doubled in the past five years ,placing a heavy burden on the national budget (employ) 5.He was very.......about this film because the main character motivated him to be more confident (excite)

Tìm x 5×(2-X)=-4×(2×X-4) 4×(X-3)-5×(2-X)=10×X-15

cho tam giác abc cân tại a. có ab=ac=5cm, bc=8cm. kẻ ah vuông góc với bc (h thuộc bc) a, chứng minh tam giác ahb bằng tam giác ahc, rồi suy ra hb=hc và góc bah= góc cah b, tính độ dài ah c, kẻ hd vuông góc với ab tại d (d thuộc ab). he vuông góc với ac tại e (e thuộc ac) . chứng minh tam giác hde là tam giác cân

Hoàn thành sơ đồ tư duy về các biện pháp bảo vệ, rèn luyện và phòng chống các bệnh ngoài da. Thêm cả phần nguyên nhân nhé

Cần gấp nha cảm ơn ae nhìu yêu...

rewrite these sentences by using conditional sentences by using conditional sentences type 1. Turn all the lights and you will not pay more money If................... 2. Unless she wears warm clothes,she will have a cold If................... 3. Be careful or you may have an accident If............ 4. Phone your parents or you have a trouble If.......... 5. Unless she whispers, everyone knows what she is saying If............ 6. Stay here and you will feel save If........... 7. Pay electricity bill today or your electricity will be cut off If......... 8. Stop smoking otherwise your cough may be worse If......... 9. Unless we use less fossil fuel, they will be run out soon If......... 10. Unless it stops raining today, we may be faced with a serious flood If......... 11. Do morning exercises regularly, your body will be fitter If........... 12. Unless we renewable energy, we will have nothing for the future generation If........ 13. The climate will change unless we reduce the use of non-renewable energy If......... 14. Lock all the doors and noone can break into your house If....