library(ggplot2)
ggplot(mtcars, aes(x = wt, y = mpg)) +
  geom_point() +
  geom_smooth(method = "lm", col = "blue") +
  labs(title = "رابطه وزن خودرو و مصرف سوخت", x = "وزن خودرو", y = "مصرف سوخت")