Tính các tổng sau : A = 1/6 + 1/12 + 1/20 + 1/30 + ... + 1/9900

Help me. Hứa vote 5 sao, cám ơn

Vẽ mầm ko cảm xúc again NL : Hóng hộ dưới bl

giúp e 9 câu trắc nhiệm này với

13. Phân tích đa thức thành nhân tử b) $4x^{2}-4x-3$ c) $4x^{2}+4x-1$ d) $x^{2}-4xy-5y^{2}$

1.been/have/goods/the/2000/supplized/that/company/since/by 2.company/twenty/worked/father/years/for/for/my/has/this

giải pt sau với x là ẩn , a,b,c là tham số $\frac{a+b-x}{c}$ + $\frac{b+c-x}{a}$ + $\frac{c+a-x}{b}$ + $\frac{4x}{a+b+c}$ = 1

Mn giúp mik nha, mik đag cần gấp

His interest is English. (He is ...) _________________________________________ 42 They take part in outdoor activities. (participate) _________________________________________ 43 He takes care of sick children. (look after) _________________________________________ 44 They take part in playing marbles. (join in) _________________________________________ 45 Let's go to the zoo. (How about ...?) _________________________________________ 46 Let's go swimming. (What about...?) _________________________________________ 47 Let's play chess tonight. (Why...?) _________________________________________ 48 Why don't you listen to music? (Let's ...) _________________________________________ 49 Would you like to go to the cinema with me tonight? (How about..?) _________________________________________ 50 How about going by car? (Let's ...)

helppppppppppppppppppppppppppppppppppppppppppppppppppppp