casandraserrat7900 casandraserrat7900 20-02-2018 Mathematics contestada 4 x + 3 y = 20 2 x + y = 7 4x+3y=20 2x+y=7 if ( x , y ) = ( a , b. (x,y)=(a,b) is a solution to the system of equations above, what is the value of b b ?