no i meant "HOW to find the substituion", not how to solve it without substitution bruhhh
i.e. they give you the same euqation. THEN the question goes "by finding a suitable substituion, solve ..."
Since theres not a lot of B6s i can only give u a really rough estimate. might be too harsh or not harsh enoguh
eng stnd - 70
eco- 75
mx1 - 43
phys - 70
madv - 85
sdd - 75
this is like 75, so can be done