Help with error in c program.

Code:

#include<stdio.h>

void get_problem(void);
void get_2pt(void);
void display2_pt(void);
void display_slope_intcpt(void);
void get_pt_slope(void);
void slope_intcpt_from2_pt(void);
void intcpt_from_pt_slope(void);
void display_pt_slope(void);

int
main(void)

{
                char any_char;
do
{

                double n1, slope, x1, y1, x2, y2, b;
                

        get_problem();

if(n1 == 1){

        get_2pt();
        display2_pt();
        slope_intcpt_from2_pt();
        display_slope_intcpt();

}else if(n1 == 2){

        get_pt_slope();
        display_pt_slope();
        intcpt_from_pt_slope();
        display_slope_intcpt();
}


        printf("\nDo you wish to calculate another vector sum?(Y/N)\n");
        scanf(" %c", &any_char);
}

while((any_char == 'y') || (any_char == 'Y'));

   return(0);
}



void
get_problem(double &n1)
{
        printf("Select the form that you would like to convert to slop-intercept form:/n");
        printf("1. Two-point form (you know two points on the line)/n");
        printf("2. Point-slope form (you know the line's slope and one point)/n");
        scanf(" %lf", &n1);
}

void
get_pt_slope(double *slope, *x1, *y1)
{
        printf("Enter the slope =>");
        scanf(" %lf", &slope);
        printf("\nEnter the x-y corrdinates of the point separated by a space =>");
        scanf(" %lf%lf", &x1, %y1);
}


void
slope_intcpt_from2_pt(double *m, x1, x2, y1, y2)
{
        m = (y2 - y1)/(x2 - x1)

}

void
display_pt_slope(double m, y1, x1)
{
        printf("Point-Slope form: \n")
        printf("y - %f = %f(x - %f)", &y1, &m, &x1)
}

void
display_slope_intcpt(double slope, b)
{
        printf("\nSlope-intercept form:\n");
        printf("y = %fx + %f", &slope, &b);
}

void
display_2pt(double y1, y2, x1, x2)
{
        printf("Two-point form: \n");
        printf("    (%f - %f)\n", &y2, &y1);
        printf("m = ---------\n");
        printf("    (%f - %f)\n", &x2, &x1);
}


void
get_2pt(double x1, x2, y1, y2)

{
        printf("Enter the x-y corrdinates of the first point separated by a space =>")
        scanf("%f%f", &x1, &y1)
        printf("Enter the x-y corrdinates of the second point separated by a space =>")
        scanf("%f%f", &x2, &y2)
}

void
intcpt_from_pt_slope(double &b)
{
 b = m*x1 + y1
}

error:

[C++ Error]Unit1.c(60): E2293 ) expected

Three of your functions above have code in them that aren't line terminated with a semicolon. Also, with an error like that, try looking at line 60. The compiler is just trying help you.

you have declared all the functions to take no arguments(void) but while defining them you're passing arguments to them.that might be the cause of the error.