Tìm x,y

a)\(\dfrac{x}{3}=\dfrac{7}{y}\)

b)\(\dfrac{x}{y}=\dfrac{1}{6}\)

c)\(\dfrac{x}{7}=\dfrac{y}{-3}\)

Tìm x

a)\(\dfrac{6}{x-3}=\dfrac{9}{2x-7}\)

b)\(\dfrac{-7}{x+1}=\dfrac{6}{x+27}\)

Tìm x biết \(\dfrac{25}{30}=\dfrac{2x+3}{6}\)

x+(x+1)+(x+2)+...+199+200=200 tìm x

Cho x∈ZSo Sánh So Sánh x²và2x

3x-2 chia hết cho x-5