Question

Решить уравнения письменно, хелп

Answer 1

5)
а)
$frac{17}{4.3 - c} = 5.1 \ 4.3 - c = 17 div 5.1 \ 4.3 - c = 17 times frac{10}{51} \ 4.3 - c = frac{10}{3} \ c = 4.3 - frac{10}{3} = frac{43}{10} - frac{10}{3} = frac{129}{30} - frac{100}{30} = frac{29}{30}$
б)
$frac{0.4}{c - frac{3}{4} } = 1 frac{1}{3} \ c - frac{3}{4} = 0.4 div 1 frac{1}{3} \ c - frac{3}{4} = frac{4}{10} div frac{4}{3} \ c - frac{3}{4} = frac{4}{10} times frac{3}{4} \ c - frac{3}{4} = frac{3}{10} \ c = frac{3}{10} + frac{3}{4} = frac{6}{20} + frac{15}{20} = frac{21}{20} = 1 frac{1}{20}$

6)
а)
$5x - frac{1}{2} = frac{5}{6} \ 5x = frac{5}{6} + frac{1}{2} \ 5x = frac{5}{6} + frac{3}{6} \ 5x = frac{8}{6} \ x = frac{8}{6} div 5 = frac{8}{6} times frac{1}{5} = frac{4}{3} times frac{1}{5} = frac{4}{15}$
б)
$2 frac{5}{6} - 5x = 1 frac{1}{3} \ 5x = 2 frac{5}{6} - 1 frac{1}{3} \ 5x = frac{17}{6} - frac{4}{3} \ 5x = frac{17}{6} - frac{8}{6} \ 5x = frac{9}{6} \ 5x = frac{3}{2} \ x = frac{3}{2} div 5 = frac{3}{2} times frac{1}{5} = frac{3}{10}$