Question

Решите уравнения (2x-7)+(6x+1)=18, 24-2(5x+4)=6, 20+4(2x-5)=14x+12, (4-8,,8x+1)=5 заранее !

Answer 1

$\displaystyle \tt (2x-7)+(6x+1)=18\\\displaystyle \tt 2x-7+6x+1=18\\\displaystyle \tt 8x-6=18\\\displaystyle \tt 8x=18+6\\\displaystyle \tt 8x=24\\\displaystyle \tt x=24\div8\\\displaystyle \tt \bold{x=3}$

$\displaystyle \tt 24-2(5x+4)=6\\\displaystyle \tt 24-10x-8=6\\\displaystyle \tt 16-10x=6\\\displaystyle \tt -10x=6-16\\\displaystyle \tt -10x=-10\\\displaystyle \tt x=-10\div(-10)\\\displaystyle \tt \bold{x=1}$

$\displaystyle \tt 20+4(2x-5)=14x+12\\\displaystyle \tt 20+8x-20=14x+12\\\displaystyle \tt 8x=14x+12\\\displaystyle \tt 8x-14x=12\\\displaystyle \tt -6x=12\\\displaystyle \tt x=12\div(-6)\\\displaystyle \tt \bold{x=-2}$

$\displaystyle \tt (4-8,2x)-(3,8x+1)=5\\\displaystyle \tt 4-8,2x-3,8x-1=5\\\displaystyle \tt 3-12x=5\\\displaystyle \tt -12x=5-3\\\displaystyle \tt -12x=2\\\displaystyle \tt x=2\div(-12)\\\\ \displaystyle \tt x=-\frac{2}{12}\\\\\displaystyle \tt \bold{x=-\frac{1}{6}}$