Rút gọn các biểu thức sau:

a, (x+3).( 2x-1) - 2x.( x-4)

b, ( 3x-2) .( 2x-3) - 5.(\(x^2\)+4)

c, 2x (\(x^2\)+1) - ( 2x-5).( \(x^2\)- 6)

16 Tìm x, biết

a) 4(x+2)-7(2x-1)+9(3x-4)=30 ; b) 2(5x-8)-3(4x-5)=4(3x-4)+11

c) 5x(1-2x)-10(x+8)=0 ; d) (5x-3).4x-2x.(10x-3)=15

tính giá trị cua biểu thức

3x(5x^2-4)+x^2(8-15x^2)-8x^2 tại x=3; x=-3

help me! cần gấp!

1 Tính:

a){4x-2(x-3)-3[x-3(4-2x)+8]}.(-3x).

b)5(3x2+4y3)+[9(2x2-y3)-2(x2-5y3)]

2 Tìm x biết:

a)5x(1-2x)-3x(x+18)=0

b)5x-3{4x-2[4x-3(5x-2)]}=182

Tìm x biết:

1. -3x(x-5)+5(x-1)+3x2=4-x

2. 7x(x-2)-5(x-1)=21x2-14x2+3

3. 3(5x-1)-x(x-2)+x2-13x=7

4. \(\dfrac{1}{5}\)x(10x-15)-2x(x-5)=12

CMR nếu (a^2+b^2+c^2)(x^2+y^2+z^2)=(ax+by+cx)^2 với xy khác 0 thì ahttps:https://LogaVN.net/image/faq/data2/216985_.https://LogaVN.net/image/faq/data2/216985_.LogaVN.nethttps://LogaVN.net/image/faq/data2/216985_.imagehttps://LogaVN.net/image/faq/data2/216985_.faqhttps://LogaVN.net/image/faq/data2/216985_.data2https://LogaVN.net/image/faq/data2/216985_.563596_.x=bhttps:https://LogaVN.net/image/faq/data2/216985_.https://LogaVN.net/image/faq/data2/216985_.LogaVN.nethttps://LogaVN.net/image/faq/data2/216985_.imagehttps://LogaVN.net/image/faq/data2/216985_.faqhttps://LogaVN.net/image/faq/data2/216985_.data2https://LogaVN.net/image/faq/data2/216985_.563596_.y=chttps:https://LogaVN.net/image/faq/data2/216985_.https://LogaVN.net/image/faq/data2/216985_.LogaVN.nethttps://LogaVN.net/image/faq/data2/216985_.imagehttps://LogaVN.net/image/faq/data2/216985_.faqhttps://LogaVN.net/image/faq/data2/216985_.data2https://LogaVN.net/image/faq/data2/216985_.563596_.z

giải CHI TIẾT

tim gia tri nho nhat C=2x^2+y^2-2x(y+1)+3

Cho tam giác ABC vuông tại A. AB=15cm, AC=20cm . Vẽ tia Axhttps:https://LogaVN.net/image/faq/data2/216985_.https://LogaVN.net/image/faq/data2/216985_.LogaVN.nethttps://LogaVN.net/image/faq/data2/216985_.imagehttps://LogaVN.net/image/faq/data2/216985_.faqhttps://LogaVN.net/image/faq/data2/216985_.data2https://LogaVN.net/image/faq/data2/216985_.563596_.https:https://LogaVN.net/image/faq/data2/216985_.https://LogaVN.net/image/faq/data2/216985_.LogaVN.nethttps://LogaVN.net/image/faq/data2/216985_.imagehttps://LogaVN.net/image/faq/data2/216985_.faqhttps://LogaVN.net/image/faq/data2/216985_.data2https://LogaVN.net/image/faq/data2/216985_.563596_.BC

và tia By vuông góc với BC tại B , tia Ax cắt By tại D

a) Chứng minh tam giác ABC~tam giác DAB

b) tính BC, DA, DB

c) AB cắt CD tại I. Tính diện tích tam giác BIC

mk cần câu c thôi

tìm x , biết

2x^2+3(x-1)(x+1)=5x(x+1)

Xác định a thỏa \(x^2+2x+3-a^2=x^2+(6-2a)x+1-a\)