Question 819990
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
 a + 2b = 773cal
 2a + b = 784cal

 -2a -4b = - 1546
 2a + b = 784
    -3b = -762
     {{{highlight( b = 254cal)}}}   and {{{highlight(a =  265cal)}}}  {{{a = 2*254-773}}}
CHECKING our answer***
 2a + b = 530cal + 254cal = 784cal