Question

Помогите пж!
Даю 50 баллов!

Answer 1

$\displaystyle 1)\frac{5x-4}{4}-\frac{x+2}{3}=2\\ \\3(5x-4)-4(x+2)=24\\ 15x-12-4x-8=24\\11x-20=24\\11x=24+20\\11x=44\\x=4\\\\2)(2x-3)(2x+3)=4x(x+1)-1\\4x^2-9=4x^2+4x-1\\-9=4x-1\\-4x=-1+9\\-4x=8\\x=-2\\\\3)\left \{ {{4(2x-y)+6=3x-y+2} \atop {5y+2(x+2y)=7y+8}} \right.\\ \\\left \{ {{x=\frac{3}{5}y-\frac{4}{5} } \atop {5y+2(x+2y)=7y+8}} \right. \\\\5y+2(\frac{3}{5}y-\frac{4}{5}+2y)=7y+8\\ \\y=3\\ \\x=\frac{3}{5}*3-\frac{4}{5}\\ \\x=1\\ (x,y)=(1,3)$