why won't this run

$```$

x $=$ df$[[\text{'}$x$\text{'}]]$

y $=$ df$[[\text{'}$y$\text{'}]]$

x$\_$train, x$\_$test, y$\_$train, y$\_$test $=$ train$\_$test$\_$split$($x$,$ y$,$ test$\_$size$=0\mathrm{.}2,$ random$\_$state$=42)$

model $=$ LinearRegression$()$

model.fix$($x$\_$train, y$\_$train$)$

y$\_$pred $=$ model.predict$($x$\_$test$)$

print$("$cooefficients:$",$ model.coef$\_)$

print$("$intercept:$",$ model.intercept$\_)$

$```$