Question

How to solve this problem

Answer 1

we have that

the system of equations is

s-y-c=300 -------> (1)s-(1)y-(1)c=300

(0)s+(1)y+(0)=150

(0)s+(0)y+(1)c=400

therefore

the answer is

1 -1 -1 300

0 1 0 150

0 0 1 400