Question 1075625
{{{B=4I}}}
.
.
.
{{{B-6=6(I-6)}}}
{{{B-6=6I-36}}}
{{{B=6I-30}}}
Substituting,
{{{4I=6I-30}}}
{{{-2I=-30}}}
Solve for I, then use either equation to solve for B.