a)\(\dfrac{6x^2y^2}{8xy^5}=\dfrac{3x}{4y^3}\)

b)\(\dfrac{10xy^2\left(x+y\right)}{15xy\left(x+y\right)^3}=\dfrac{2y}{3\left(x+y\right)^2}\)

c)\(\dfrac{2x^2+2x}{x+1}=\dfrac{2x\left(x+1\right)}{x+1}=2x\)

d)\(\dfrac{x^2-xy-x+y}{x^2+xy-x-y}=\dfrac{x\left(x-y\right)-\left(x-y\right)}{x\left(x+y\right)-\left(x+y\right)}=\dfrac{x-y}{x+y}\)

2. taught

3. sold

4.fell-hurt

5.threw-caught 

6. spent-bought-cost