I'll take this challenge since I'm not feeling lazy for once.... x would represent Gavin and y would represent Seiji.
a.
b. I will solve your system using substitution.
<span>Step 1: Solve </span>
for x
(add -y for both sides)
<span>Step 2: substitute </span>
for x in 
<span></span>
(simplify both sides of the equation)
(add -425 to both sides)<span>
</span>
y=200
step 3: substitute 200 for y in
c. Already answered with the picture that is attached.
d. Gavin earned 225 dollars while Seiji earned 200 dollars.
a.
b. I will solve your system using substitution.
<span>Step 1: Solve </span>
<span>Step 2: substitute </span>
<span></span>
</span>
y=200
step 3: substitute 200 for y in
c. Already answered with the picture that is attached.
d. Gavin earned 225 dollars while Seiji earned 200 dollars.