Question

Post your question here (Keep it simple and clear to get the best answers)x+2y=7,x-2y=1

Answer 1

x+2y=7-equation 1
x-2y=1-equation 2

equation 1-2
x+2y=7
x-2y=1
now,
    look in eq 2
there +x becomes -x
         -2y becomes +2y
         +1 becomes -1
                             so,
 both x cancels, 2y+2y=4y    
                          7-1=6
                    so 4y=6
                          y=6\4
                          y=3\2
from equation 1 (or u may take 2)
                 x+2y=7
                 x+2(3\2)=7
                 x+3=7
                   x=7-3
                  x=4