用c语言函数调用的方法编程设有函数y=f(x),任给一个实数x，求y的值。其中：f(x)=g(x)-7 g(x)=h(x)+8 h(x)=x3-2x

Sure, I can help! Here's the C code for the function y=f(x), where f(x) = g(x) - 7, g(x) = h(x) + 8, and h(x) = x^3 - 2x:

#include <stdio.h>

// Define the function h(x)
double h(double x) {
    return x*x*x - 2*x;
}

// Define the function g(x)
double g(double x) {
    return h(x) + 8;
}

// Define the function f(x)
double f(double x) {
    return g(x) - 7;
}

int main() {
    double x = 2.0; // Replace 2.0 with whatever value of x you want to use
    double y = f(x); // Call the function f(x) to get the value of y

    printf("y = %lf\n", y); // Print the value of y
    return 0;
}

To use this code, simply replace the value of x in the main function with whatever value you want to use, and then run the code to get the value of y. Note that you may need to adjust the format specifier in the printf statement depending on the precision of the value you get.