The two equations for the given conditions are:

 n +  m = 20    (1)

2n + 4m = 64    (2)



(2) -->  n + 2m = 32



Subtract (1) from this to get m:

  n + 2m  = 32

- n  - m  = -20

------------------

  (you do the rest here)



 then plug in that value into (1) or (2) and solve for n.  





----

Don't forget to check your answer

 



  

RELATED QUESTIONS

The sum of two numbers is 20. Twice the first number plus four times the second is 64.... (answered by ikleyn)

The sum of two numbers is -7. Four times first number plus twice the second number is -8.  (answered by rfer)

The sum of twice a number and three times another number is 120. Four times the first... (answered by stanbon)

The sum of two numbers is 39.Twice the first number plus three times the second number is  (answered by scott8148)

The sum of two numbers is 37.  The first number is four more than twice the second.  Find  (answered by algebrahouse.com)

The sum of three numbers is 10. Two times the second number minus the first number is... (answered by lwsshak3)

The sum of Two numbers is 39.Twice the first number and plus 3 times the second number is  (answered by ursuchacrass)

Three times a number plus twice a second number is 41. Also, four times the first plus... (answered by Mathtut)

the sum of two is -1. when twice the first number and four times the second numbers are... (answered by ankor@dixie-net.com)