Linear Equations: Nutrients problem

Find how many grams of beef, bread and cheese you must take in order to obtain 100g protein, 380g starch and 38g fat and find the total number of calories.
/* Nutrients problem */

VAR  a     "Beef      [g]" ..
    ,b     "Bread     [g]" ..
    ,c     "Cheese    [g]" ..
    ,K     "Calorie [cal]"

0.21*a + 0.09*b + 0.23*c = 100  /* Protein (g) */
         0.58*b + 0.01*c = 380  /* Starch  (g) */
0.06*a + 0.02*b + 0.26*c = 38   /* Fat     (g) */

1.5 *a + 2.7 *b + 3.6 *c = K
Explanation

The VAR statement defines variables. The double quotation mark ( " ) is used for descriptions such as the output of calculation results.

.. means the continuation of a statement, and multiple statements or equations can be written.

Without the OUTPUT statement, all the variable values will be output.

Enter equations and click on the [Solve] button.

/* Nutrients */ VAR a "Beef [g]" .. ,b "Bread [g]" .. ,c "Cheese [g]" .. ,K "Calorie [cal]" 0.21*a + 0.09*b + 0.23*c = 100 /* Protein (g) */ 0.58*b + 0.01*c = 380 /* Starch (g) */ 0.06*a + 0.02*b + 0.26*c = 38 /* Fat (g) */ 1.5 *a + 2.7 *b + 3.6 *c = K

Sample problem

The following sample problems will help you understand how EQUATRAN-G works.

Linear equations: Tsuru-Kame-Zan (Japanese traditional problem, means problem of cranes and tortoises); Nutrients problem
Non-linear equations: Root of 3rd order polynomial equation; Loan calculation
Ordinary differential equations: 2nd order ordinary differential equation
Optimization and least square problems: Approximation in 3rd order polynomial equation