Question 408030
{{{A = ba/2}}} ==> {{{2(dA/dt) = (db/dt)a + b(da/dt)}}}
{{{dA/dt = 3 cm^2/min}}}, {{{da/dt = 2.5 cm/min}}}.
When a = 7 cm and A = {{{88 cm^2}}}, b = {{{176 cm/7 }}}.
Now you got everything you need to find {{{db/dt}}}.
Good luck!