Write \((1+2\sqrt{5})(4−\sqrt{5})\) in the form \(a+b\sqrt{5}\) where \(a\) and \(b\) are integers. - চর্চা

Write \((1+2\sqrt{5})(4−\sqrt{5})\) in the form \(a+b\sqrt{5}\) where \(a\) and \(b\) are integers. - চর্চা