x^2+2x+3=x^2+2x+1+2
=(x+1)^2+2>=2
Dấu = xảy ra khi x=-1
x^2+2x+3=x^2+2x+1+2
=(x+1)^2+2>=2
Dấu = xảy ra khi x=-1
tìm x, biết:
e) \(\dfrac{2}{7-x}\)=\(\dfrac{18}{45}\) f)\(\dfrac{2x+3}{3}\)=\(\dfrac{50}{15}\) g)\(2\dfrac{x}{7}\)=\(\dfrac{75}{35}\) h)\(2\dfrac{3}{x}\)=\(\dfrac{13}{x}\)(x khác 0)
2 tìm x
a) x+25=40
b) 198-(x+4)=120
c) (2x-7).3=125
d) x +16⋮x+1
\(\dfrac{x}{2}\)-(\(\dfrac{3x}{5}\)-\(\dfrac{13}{5}\))=-(\(\dfrac{7}{5}\)+\(\dfrac{7}{10}\).\(x\))
\(\dfrac{2x-3}{3}\)+\(\dfrac{-3}{2}\)=\(\dfrac{5-3x}{6}\)-\(\dfrac{1}{3}\)
\(\dfrac{2}{3x}\)-\(\dfrac{3}{12}\)=\(\dfrac{4}{5}-\left(\dfrac{7}{x}-2\right)\)
Tìm x \(\in\) Z để phân số \(\dfrac{3+2x}{1+x}\) có giá trị lớn nhất.
giúp mình với
x-1/3 + 3x-5/2 + 2x/9 + (-5x)/9
tính tổng:
a,1/2 x 3+1/2 x 4+1/2 x 5+...+1/9 x 10
b,3/2 x 5+3/6 8+...+3/23 x 28
giải nhanh hộ mik nha
Bài 1 : Tìm x
a, x/3 = 2/3 + -3/7
b, x/7 = -3/4 + 2/-9
Mn giúp mk với !
f) \(\dfrac{x+1}{x-3}=\dfrac{x+7}{x-2}\)
\(\dfrac{x}{-8}=\dfrac{2}{-x^3}\) (\(x\ne0\))