From the first equation, we know that r and s are in the ratio 3:7.
Trial substitution of 3 and 7 into the second equation gives 58, which means that 3 and 7 are the solutions for r and s respectively.
By elimination:
7r-3s=0...(1)
3r+7s=58...(2)
Use linear combination to eliminate r: 7(2)-3(1)
21r+49s-(21r-9s)=58*7
58s=58*7
s=7
Substitute s=3 in (1)
7r-3(7)=0
r=3(7)/7=3
this gives
r=3, s=7.
solve the elimination method 7r-3s=0
3r+7s=58
what is the solution of the system
2 answers
-rs^3-r^3s=