Question

Помогите пожалуйста решить на листке написать и фотографировать

Answer 1

$\underline {544}.\quad 0,69= \frac{5-2y}{8} \cdot 13,8\\\\0,69\cdot 8=(5-2y)\cdot 13,8\\\\5,52=69-27,6y\\\\27,6y=63,48\\\\y=63,48:27,6\\\\y=2,3\\\\\underline {545}.\quad \frac{2x+1}{x} -5=- \frac{4x}{2x+1} \quad \; ODZ:\; x\ne -\frac{1}{2},\; x\ne 0\\\\ \frac{2x+1-5x}{x}=- \frac{4x}{2x+1} \\\\(1-3x)(2x+1)=-4x^2\\\\2x+1-6x^2-3x=-4x^2\\\\2x^2+x-1=0\\\\D=1+8=9,\; \; x_1= \frac{-1-3}{4}=-\frac{4}{4}=-1 \\\\x_2= \frac{-1+3}{4} = \frac{2}{4} =\frac{1}2}=0,5$

$\underline {547}.\quad x:12=144\\\\ \frac{x}{12} =144\\\\x=12\cdot 144\\\\x=1728\\\\\underline {550}.\quad \frac{3x+1}{2} = \frac{2x-3}{5} \\\\5\cdot (3x+1)=2\cdot (2x-3)\\\\15x+5=4x-6\\\\11x=-11\\\\x=-1$