Code:Hello all, Thank you all for taking some time to read and help. I have just started programming in c++. I tried to make a program to solve two simulataneous eqns for eg ( 3x + y = 7, x - 2y =0... What is x and y?) I figured the only way to program this is to use the matrices method, which is finding the det and so on and so forth. Here is the source code ( x is the determinant) #include <iostream> using namespace std; int main() { double a; double b; double c; double a1; double b1; double c1; double x = (1 / ((a * b1) - (b * a1))); cout<<"What is a? :"; cin>> a; cout<<"What is b? :"; cin>> b; cout<<"What is c? :"; cin>> c; cout<<"What is a1? :"; cin>> a1; cout<<"What is b1? :"; cin>> b1; cout<<"What is c1 :"; cin>> c1; cout<<"X = "<< (x * c * b1) + (x * c1 * -b); cin.ignore(); cin.get(); return 0; } I tried it the forumula on paper and i can solve the problems fine but i cant seem to make it work.. i get answers like = -1.#IF or something like dat .. I really dont know what im doing wrong. So please help me out here Thanks alot ps : this is supposed to find the value of X only(not the determinant) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~EDIT~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For those of you who do not understand how this is supposed to work... here is an example 3x + y = 5 x - 2y = -3 therefore... a=3(coeff of x first line) b=1(coeff of y first line) c= 5 a1=1(coeffe of x 2nd line) b1= -2(coeff of y 2nd line) c1 = -3