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)
a) \(\left(x+3\right)\left(2x-1\right)-2x\left(x-4\right)\)
\(=2x^2-x+6x-3-2x^2+8x\)
\(=13x-3\)
b) \(\left(3x-2\right)\left(2x-3\right)-5\left(x^2+4\right)\)
\(=6x^2-9x-4x+6-5x^2-20\)
\(=x^2-13x-14\)
c) \(2x\left(x^2+1\right)-\left(2x-5\right)\left(x^2-6\right)\)
\(=2x^3+2x-\left(2x^3-12x-5x^2+30\right)\)
\(=2x^3+2x-2x^3+12x+5x^2-30\)
\(=5x^2+14x-30\)
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 \(x^2+2x+3-a^2=x^2+(6-2a)x+1-a\)
4x(5-x)-8x(5-x)=0
Loga.vn - Cộng Đồng Luyện Thi Trực Tuyến