Answer:
Computer costs 812, printer costs 406
Step-by-step explanation:
Let c represent the cost of a computer and p, the cost of a printer
c + p = 1218 ....eq 1
but,
c = 2p ...eq 2
Substitute the value of c in eq 1
2p + p = 1218
3p = 1218
Divide both sides by p
p = 406
Substitute the value of p in eq 2
c = 2 * 406
c = 812