Answer:
Below
Explanation:
You have ONE equation and TWO unknowns, so there is infinite solutions for a and c......you cannot solve for a specific a and c unless you have another equation relating the two or a definition of one of them.
You can Solve for a
20a + 15 c = 340
20 a = 340-15c
a = ( 340 -15c) / 20 = 17 - 3/4 c
Similarly:
20 a + 15 c = 340
15c = 340 - 20 a
c = (340-20a)/15