Algebra

 

Let x and y be integers.  If x and y satisfy 37x + 82y = -172 and x + y = -1, then find x.    

 

 

                                            37x + 82y = –172    

                                                x   +   y =     –1    ==>>    y = –x – 1     

substitute (–x – 1) for y   

in the other equation    

                                            37x + 82(–x – 1)  =  –172    

                                            37x – 82x – 82     =  –172    

                                                              – 45x  =  – 90     

 

                                                                      x  =  2    

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