Aritmética preguntas y respuestas

Evaluate \( a-b \) if \( a=-2.5 \) and \( b=\frac{2}{5} \). Write your answer as a decimal to the nearest tenth.

\( x-y \) if \( x=-5 \frac{1}{4} \) and \( y=-6.8 \). Write your answer as a decimal to the nearest hundredth.

Сравните числа: \( \begin{array}{lll}\text { а) } \frac{11}{20} \text { и } \frac{7}{12} ; & \text { б) } \frac{11}{18} \text { и } \frac{11}{19} ; & \text { в) } 0,48 \text { и } \frac{25}{24}\end{array} \) \( \begin{array}{lll}\text { Найдите значение выражения: } \\ \begin{array}{lll}\text { а) } \frac{11}{50}-\frac{3}{25}+\frac{1}{20} ; & \text { в) } 2 \frac{1}{8}+3 \frac{5}{12} ; & \text { д) } 7 \frac{3}{8}-3 \frac{5}{6}\end{array} \\ \begin{array}{lll}\text { б) } 8-3 \frac{6}{7} ; & \text { г) } 5 \frac{13}{15}+1 \frac{7}{12} ;\end{array} \\ \text { На автомашине планировали перевезти сначала } 3 \frac{8}{9} \text { т груза, а г } \\ \text { том ещё } 2 \frac{11}{18} \text { т. Однако перевезли на } 1 \frac{1}{4} \text { т меньше, чем предпол }\end{array} \) гали. Сколько всего тонн груза перевезли на автомашине? Решите уравнение: а) \( x-2 \frac{8}{15}=3 \frac{7}{12} ; \) б) \( 3,45 \cdot(2,08-k)=6,2 \) Найдите четыре дроби, каждая из которых больше \( \frac{5}{9} \) и меғ ше \( \frac{7}{9} \).

10. A girl swims 400 m in still water and then returns to the initial point (from where she started) in 20 minutes. Determine the speed of the girl. 11. A man is running at a speed of \( 3 \mathrm{~m} / \mathrm{s} \) and covers some distance in 15 sec . Find the time taken by his pet dog to cover the same distance at a speed of \( 10 \mathrm{~m} / \mathrm{s} \).

Find \( \frac{5}{6}-\left(-\frac{3}{4}\right) \). Write your answer as a mixed number in simplest form.

Find \( -\frac{8}{15}-3 \frac{4}{5} \). Write your answer as a mixed number in simplest form.

Find \( -\frac{7}{8}-2 \frac{1}{6} \). Write your answer as a mixed number in simplest form

\( ( 7 \times 5 ) \quad \bmod 6 \)

QUESTION TWO Express each of the following as a single, simplified fraction. 2.1. \( \frac{4}{9}-\frac{2}{3}+\frac{7}{12} \) 2.2. \( \frac{-8}{13} \times \frac{5}{24} \div-\frac{25}{13} \) 2.3. \( \left(\frac{3}{7}+\frac{1}{4}\right) \times\left(2-\frac{69}{38}\right) \)

(f) \( \frac{1}{6} \times \frac{3}{8}-\frac{1}{10} \)