Упр.228 ГДЗ Муравин 7 класс (Алгебра)

1) (3/7)^2 · 0,49 + (0,1)^3 · 210;
2) 2^5 · 3^3 : 180;
3) 240 : (-2/3)^3 — 50 : (-0,5)^2;
4) (-0,3)^3 · 0,5^2 + (-0,5)^2 · 0,4^3.

1. $$\left(\frac{3}{7}\right)^2 \cdot 0{,}49 + (0{,}1)^3 \cdot 210 = \frac{9}{49}\cdot \frac{49}{100} + 0{,}001 \cdot 210$$
   $$= \frac{9}{100} + 0{,}21 = 0{,}09 + 0{,}21 = 0{,}3.$$
2. $$2^5 \cdot 3^3 : 180 = \frac{2^5 \cdot 3^3}{180} = \frac{32 \cdot 27}{180} = \frac{864}{180} = 4{,}8.$$
3. $$240 : \left(-\frac{2}{3}\right)^3 — 50 : (-0{,}5)^2 = 240 : \left(-\frac{8}{27}\right) — 50 : 0{,}25$$
   $$= 240 \cdot \left(-\frac{27}{8}\right) — 200 = -30 \cdot 27 — 200 = -810 — 200 = -1010.$$
4. $$(-0{,}3)^3 \cdot 0{,}5^2 + (-0{,}5)^2 \cdot 0{,}4^3 = 0{,}5^2 \cdot \left((-0{,}3)^3 + 0{,}4^3\right)$$
   $$= 0{,}25 \cdot (-0{,}027 + 0{,}064) = 0{,}25 \cdot 0{,}037 = 0{,}00925.$$

Ответ

1) $$0{,}3$$; 2) $$4{,}8$$; 3) $$-1010$$; 4) $$0{,}00925$$.