How to get numeri8c value of output variable in linear regression

linear_regression
r

#1

I am currently working on linear regression problem I want to see the effect of remaining variable on the output variable but I am getting the effect of each variable individually on the output variable I want combine effect
white<-read.csv(“white.csv”)
head(white)
red<-red.csv(“red.csv”)
m1<-lm(quality~.,data=white)
plot(quality~.,data=white)
my output variable is quality