Упр.5.536 ГДЗ Виленкин Жохов 5 класс Часть 2, Просвещение (Математика)

1) (3х + 5x) · 45 = 1080; 3) (10z — 4z) : 4 = 12;
2) (9x — 4x) · 72 = 1080; 4) (8z + 10z) : 9 = 16.

1) $$ (3x + 5x)\cdot 45 = 1080 $$

Сложим подобные слагаемые:

$$ 8x \cdot 45 = 1080 $$

$$ 8x = 1080 : 45 $$

$$ 8x = 24 $$

$$ x = 24 : 8 $$

$$ x = 3 $$

2) $$ (9x — 4x)\cdot 72 = 1080 $$

$$ 5x \cdot 72 = 1080 $$

$$ 5x = 1080 : 72 $$

$$ 5x = 15 $$

$$ x = 15 : 5 $$

$$ x = 3 $$

3) $$ (10z — 4z) : 4 = 12 $$

$$ 6z : 4 = 12 $$

$$ 6z = 12 \cdot 4 $$

$$ 6z = 48 $$

$$ z = 48 : 6 $$

$$ z = 8 $$

4) $$ (8z + 10z) : 9 = 16 $$

$$ 18z : 9 = 16 $$

$$ 2z = 16 $$

$$ z = 16 : 2 $$

$$ z = 8 $$

Ответ

1) $$x = 3$$; 2) $$x = 3$$; 3) $$z = 8$$; 4) $$z = 8$$.