Question

a) 5/7a+3/14a при а =4целых2/3;7/13
б) 3/8y+y-1/4y при y = 2целых2/3;4/9

Answer 1

a)
 $frac{5}{7}a+ frac{3}{14} a = ( frac{5}{7} + frac{3}{14} )*a = ( frac{5*2 + 3}{14})*a= frac{13}{14}a$

$a= 4 frac{2}{3} \ \ frac{13}{14} *4 frac{2}{3} = frac{13*14}{14*3} = frac{13}{3} = 4 frac{1}{3}$

$a= frac{7}{13} \ \ frac{13}{14} * frac{7}{13} = frac{1*1}{2*1} = frac{1}{2}$

б)
$frac{3}{8} y + y - frac{1}{4} y = ( frac{3}{8} +1 - frac{2}{8} )y = 1 frac{1}{8} y$

$y=2 frac{2}{3} \ \ 1 frac{1}{8}* 2 frac{2}{3}= frac{9}{8} * frac{8}{3} =3$

$y= frac{4}{9} \ \ 1 frac{1}{8}* frac{4}{9}= frac{9}{8} * frac{4}{9} = frac{1}{2}$