Question

ПОМОГИТЕ ПОЖАЛУЙСТА НОМЕР 1458

Answer 1

1458. Розв'язати рівняння:

1.

$frac{5}{12}x-0,7=2,4-frac{4}{9}x \\frac{5}{12}x+frac{4}{9}x= frac{7}{10}+frac{12}{5}\\ frac{5cdot 3+4cdot 4}{36}x= frac{7+2cdot 12}{10} \\ frac{31}{36}x= frac{31}{10} \\ frac{31}{36}x= frac{31}{10} \\x = frac{31}{10}:frac{31}{36} = frac{36}{10}cdot frac{36}{31} = frac{31}{10} = 3frac{6}{10}=3,6\\x=3,6$

2.

$frac{1}{8}x-frac{1}{4}x=frac{1}{16}x-3\\frac{1}{8}x-frac{1}{4}x-frac{1}{16}x=-3\\frac{2-4-1}{16}x=-3\\-frac{3}{16}x=-3 : | cdot (-16)\\3x=48\\x = 16$

3.

$2frac{1}{2} x-3=-4frac{1}{2}x-3frac{1}{3}\\frac{5}{2}x+frac{9}{2}x=3-3frac{1}{3}\\frac{14}{2}x = -frac{1}{3} \\7x = -frac{1}{3} \\x=-frac{1}{3}:7 \\x=-frac{1}{3}cdot frac{1}{7} = -frac{1}{21}\\x= -frac{1}{21}$

4.

$frac{3}{5}left(2frac{7}{9}x+3frac{1}{3}right)=frac{1}{6}x+6frac{1}{2}\\frac{3}{5}left(frac{25}{9}x+frac{10}{3}right)=frac{1}{6}x+frac{13}{2}\\frac{75}{45}x+frac{30}{15} = frac{1}{6}x+frac{13}{2}\\frac{5}{3}x - frac{1}{6}x =frac{13}{2}-2\\frac{10-1}{6}x =frac{13-4}{2}\\frac{9}{6}x =frac{9}{2} \\frac{3}{2}x =frac{9}{2} \\x = frac{9}{2}:frac{3}{2} = frac{9}{2}cdot frac{2}{3} =frac{9}{3} = 3 \\x=3$