Question 1024850
Try more conventional variables choice.
s for small, L for large.
{{{system(0.20s+0.35L=7.50,s+L=30)}}}


{{{(1/0.05)(0.2s+0.35L)=(1/0.05)7.50}}}
{{{4s+7L=150}}}


Revised system, {{{system(s+L=30,4s+7L=150)}}}
Can you finish from this?