Question

помогите с номером 85(3-4)

Answer 1

3) $4sqrt{9*3b}-5sqrt{16*3b}+ frac{1}{4}sqrt{16*4*3b}=4*3sqrt{3b}-5*4sqrt{3b}+ frac{4*2}{4}sqrt{3b}=sqrt{3b}*(12-20+2)=-6sqrt{3b}$

4) $7xsqrt{7^{2}*x^{2}*y^{4}*xy}+3x^{2}ysqrt{8^{2}*y^{2}*y}-5sqrt{6^{2}*x^{4}*y^{4}*xy}=49x^{2}*y^{2}sqrt{xy}+24x^{2}y^{2}sqrt{y}-30x^{2}*y^{2}sqrt{xy}=x^{2}y^{2}sqrt{y}*(49sqrt{x}+24-30sqrt{x})=x^{2}y^{2}sqrt{y}*(19sqrt{x}+24)$