Question 1204812



{{{(2y - 5)*(5y - 2)^6}}}....expand

={{{(2y - 5)*(15625y^6 - 37500y^5 + 37500y^4 - 20000y^3 + 6000y^2 - 960y + 64)}}}

={{{31250y^7 - 153125y^6 + 262500y^5 - 227500y^4 + 112000y^3 - 31920y^2 + 4928y - 320}}}


 the coefficient of {{{y^4 }}}is: {{{- 227500}}}