How can we use the intercept and slope of a regression to pr

How can we use the intercept and slope of a regression to predicts the future value of a dependent variable?

let us take the regression line of Y on X as Y=a+bX

here X- independent variable Y- dependent variable a- y-intercept and b-slope

substituting future values of X then we will get the future value of Y ( by multiplying x value with the slope and adding to the intercept)

example Y= 5+3X if x=4 then Y=5+3(4) =17 in the same way we will get future or past values by using slope and intercept of regression