Please please please help me :(

Question

Addition and Multiplication of Complex Numbers

#include<stdio.h>

int main()
{ float R1,I1,R2,I2;
printf("please enter the real part of first number");
scanf("%f",&R1);
printf("please enter the imeginery part of first number");
scanf("%f",&I1);
printf("please enter the real part of second number");
scanf("%f",&R2);
printf("please enter the imeginery part of second number");
scanf("%f",&I2);
float add (R1,R2,I1,I2);
float mult (R1,R2,I1,I2);
}

float add (float R1, float R2, float I1,float I2) {
float R=R1+R2;
float I=I1+I2;
printf("%f",R"+%f i");
}
float mult (float R1, float R2, float I1,float I2) {
float R=(R1+R2)-(I1+I2);
float I=(R1*I2)+(R2*I1);
printf("%f",R"+%f i");
}

Answer 1

that's a lot of errors, ugh.
I can see you aren't taking any C course.
please re-learn to the course because there's so many basic errors that you have done, that can be avoided in near future if you re-learning the course, especially the functions section