library(gridExtra)

library(ggplot2)

p1<-ggplot(data=mtcars,aes(x=mtcars$mpg,y=mtcars$hp)) + geom_point()

p2<-ggplot(data=cars,aes(x=cars$speed,y=cars$dist)) + geom_point()

grid.arrange(p1,p2,ncol=2)