Violympic toán 7
Các câu hỏi tương tự
Tìm x
\(\left(2x+3\right)^2-\left(5x-4\right)\left(5x+4\right)=\left(x+5\right)^2-\left(3x-1\right)\left(7x+2\right)-\left(x^2-1+1\right)\)
Tìm nghiệm của các đa thức sau:\(F\left(x\right)=3x-6\); \(H\left(x\right)=-5x+30\); \(G\left(x\right)=\left(x-3\right)\left(16-4x\right)\); \(K\left(x\right)=x^2-81\); \(M\left(x\right)=x^2+7x-8\); \(N\left(x\right)=5x^2+9x+4\)
Tìm x,y biết a) \(\frac{x}{18}=\frac{y}{15}\) và x-y=-30 b) 7x=9y và 10x-8y=68 c) \(\left(x-\frac{1}{2}\right)^{^{50}}+\left(y+\frac{1}{3}\right)^{^{40}}=0\)
Làm phép chia:
\(a,15x^3y^5z:5x^2y^3\)
\(b,12x^4y^2:\left(-9xy^2\right)\)
\(c,\left(30x^4y^3-25x^2y^3-3x^4y^4\right):5x^2y^3\)
\(d,\left(4x^4-8x^2y^2+12x^5y\right):\left(-4x^2\right)\)
Tìm x,y,z biết:
a) \(\dfrac{x}{3}=\dfrac{z}{8}\); -6y = 7z và 2x - 9y = 2
b) \(\left|4-2x\right|+\left|x-2\right|=3-x\)
c) (5x-3)2013 = (5x-3)2015
tìm x
a)\(5x\left(\frac{1}{5}x-2\right)+3\left(6-\frac{1}{3}x^2\right)=12\)
b)\(7x\left(x-2\right)-5\left(x-1\right)=7x^2+3\)
Bài 1: Thu gọn
a) frac{1}{5}x^4y^3-3x^4y^3
b) 5x^2y^5-frac{1}{4}x^2y^5
c) frac{1}{7}x^2y^3.left(-frac{14}{3}xy^2right)-frac{1}{2}xy.left(x^2y^{text{4}}right)
d) left(3xyright)^2.left(-frac{1}{2}x^3y^2right)
e) -frac{1}{4}xy^2+frac{2}{5}x^2y+frac{1}{2}xy^2-x^2y
f) frac{1}{2}x^4y.left(-frac{2}{3}x^3y^2right)-frac{1}{3}x^7y^3
g) frac{1}{2}x^2y.left(-10x^3yz^2right).frac{1}{4}x^5y^3z
h) 4.left(-frac{1}{2}xright)^2-frac{3}{2}x.left(-xright)+frac{1}{3}x^2
i) 1frac{2}{3}x^3y.left(frac{-1}{2}xy...
Đọc tiếp
Bài 1: Thu gọn
a) \(\frac{1}{5}x^4y^3-3x^4y^3\)
b) \(5x^2y^5-\frac{1}{4}x^2y^5\)
c) \(\frac{1}{7}x^2y^3.\left(-\frac{14}{3}xy^2\right)-\frac{1}{2}xy.\left(x^2y^{\text{4}}\right)\)
d) \(\left(3xy\right)^2.\left(-\frac{1}{2}x^3y^2\right)\)
e) \(-\frac{1}{4}xy^2+\frac{2}{5}x^2y+\frac{1}{2}xy^2-x^2y\)
f) \(\frac{1}{2}x^4y.\left(-\frac{2}{3}x^3y^2\right)-\frac{1}{3}x^7y^3\)
g) \(\frac{1}{2}x^2y.\left(-10x^3yz^2\right).\frac{1}{4}x^5y^3z\)
h) \(4.\left(-\frac{1}{2}x\right)^2-\frac{3}{2}x.\left(-x\right)+\frac{1}{3}x^2\)
i) \(1\frac{2}{3}x^3y.\left(\frac{-1}{2}xy^2\right)^2-\frac{5}{4}.\frac{8}{15}x^3y.\left(-\frac{1}{2}xy^2\right)^2\)
k) \(-\frac{3}{2}xy^2.\left(\frac{3}{4}x^2y\right)^2-\frac{3}{5}xy.\left(-\frac{1}{3}x^4y^3\right)+\left(-x^2y\right)^2.\left(xy\right)^2\)
n) \(-2\frac{1}{5}xy.\left(-5x\right)^2+\frac{3}{4}y.\frac{2}{3}\left(-x^3\right)-\frac{1}{9}.\left(-x\right)^3.\frac{1}{3}y\)
m) \(\left(-\frac{1}{3}xy^2\right)^2.\left(3x^2y\right)^3.\left(-\frac{5}{2}xy^2z^3\right)^{^2}\)
p) \(-2y.\left|2\right|x^4y^5.\left|-\frac{3}{4}\right|x^3y^2z\)
Tìm số nguyên x biết \(\left|2x+4\right|+\left|5x+10\right|\le\dfrac{5}{7}\)
Tìm đa thức M , biết :
a) \(M-\left(\frac{1}{2}x^2y-5xy^2+x^3-y^3\right)=\frac{3}{4}xy^2-2x^2y+\)\(2y^3-\frac{1}{3}x^3\)
b)\(\left(-\frac{1}{3}x^3y^3+5x^2y^2-\frac{5}{2}xy\right)-M=xy-\frac{1}{6}x^3y^3-3x^2y^2\)
c)\(\left(\frac{2}{7}xy^4-5x^5+7x^2y^3-3\right)+M=0\)