40 points is (4,7) a solution of equations? explain your answer 2x+4y=36 3x-4y=-6

2x + 4y = 36
3x - 4y = -6
add
5x = 30 
  x = 6

2x+4y=36 
2(6)+4y=36 
12 + 4y = 36
4y = 24
  y = 6

answer
(6, 6) is a solution of equations
(4,7) is NOT a solution of equations

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm