Question 1192852
<pre>

{{{A}}}{{{""=""}}}{{{expr(1/2)h(b[1] + b[2])}}}

Clear the fraction by multiplying both sides by 2:

{{{2*A}}}{{{""=""}}}{{{2*expr(1/2)h(b[1] + b[2])}}}

{{{2A}}}{{{""=""}}}{{{cross(2)*expr(1/cross(2))h(b[1] + b[2])}}}

{{{2A}}}{{{""=""}}}{{{h(b[1] + b[2])}}}

{{{2A}}}{{{""=""}}}{{{h*b[1] + h*b[2])}}}

{{{2A-h*b[2]}}}{{{""=""}}}{{{h*b[1]}}}

Multiply both sides by {{{1/h}}}:

{{{expr(1/h)(2A-h*b[2])}}}{{{""=""}}}{{{expr(1/h)h*b[1]}}}

{{{expr(1/h)(2A-h*b[2])}}}{{{""=""}}}{{{expr(1/cross(h))cross(h)*b[1]}}}

{{{expr(1/h)(2A-h*b[2])}}}{{{""=""}}}{{{b[1]}}}

{{{b[1]}}}{{{""=""}}}{{{expr(1/h)(2A-h*b[2])}}}

Edwin</pre>