Question

Решите как можно больше заданий. Очень очень нужно.

Answer 1

$1) frac{y}{15}+3 = frac{y+153}{45}\ \ frac{y + 45}{15} - frac{y+153}{45} = 0\ \ frac{3(y+45) -y-153}{45}=0\ \ frac{3y+135 -y-153}{45}=0\ \ frac{2y-18}{45}=0\ \ 2y -18=0\ 2y =18\ y=9$

 

$2) (2frac{1}{2}-1frac{3}{8})*(3frac{1}{2}-frac{3}{6})*1frac{1}{3}=(frac{5}{2}-frac{11}{8})*(frac{7}{2}-frac{3}{6})*frac{4}{3}=\ \ =(frac{20-11}{8})*(frac{21-3}{6})*frac{4}{3}=frac{9}{8}*frac{18}{6}*frac{4}{3}=frac{3}{2}*3=frac{9}{2} = 4.5$

 

$3) (1.7:(1frac{2}{3}-3.75)):frac{8}{25} = 1frac{5}{12}\ \ (frac{17}{10}:(frac{5}{3}-frac{15}{4} )):frac{8}{25} = frac{17}{12}\ \ (frac{17}{10}:(frac{20x-45}{12} )):frac{8}{25} = frac{17}{12}\ \ frac{17}{10}*(frac{12}{5(4x-9)})*frac{25}{8} = frac{17}{12}\ \ frac{17}{2}*(frac{3}{4x-9} )*frac{1}{2} = frac{17}{12}\ \ frac{51}{4(4x-9)}= frac{17}{12}\ \ 51*12 = 17 * 4(4x-9)\ 612 = 272x-612\ 612 + 612 - 272x =0\ 272x=1224\ x = 1224 : 272\ x = 4.5$