1. Вычислите:
1) $$37\cdot218 + 63\cdot218 = 218\cdot(37+63) = 218\cdot100 = 21800$$
2) $$568\cdot43 - 566\cdot43 = 43\cdot(568-566) = 43\cdot2 = 86$$
3) $$417\cdot187 + 417\cdot213 = 417\cdot(187+213) = 417\cdot400 = 166800$$
4) $$52\cdot187 - 43\cdot52 - 52\cdot4 = 52\cdot(187-43-4) = 52\cdot140 = 7280$$
2. Примените распределительное свойство умножения:
1) $$3(a+8) = 3a + 3\cdot8 = 3a + 24$$
2) $$8(6-y) = 8\cdot6 - 8y = 48 - 8y$$
3) $$(x-9)\cdot11 = 11x - 9\cdot11 = 11x - 99$$
3. Упростите выражение:
1) $$5x + 7x = (5+7)x = 12x$$
2) $$17a - 9a = (17-9)a = 8a$$
3) $$34a - a = (34-1)a = 33a$$
4) $$c + 72c = (1+72)c = 73c$$
5) $$7x + 8x + 12x = (7+8+12)x = 27x$$
6) $$53y + 18y - 24y = (53+18-24)y = 47y$$
7) $$14m + 15m + 16 = (14+15)m + 16 = 29m + 16$$
8) $$69n - n - 18 = (69-1)n - 18 = 68n - 18$$
9) $$25x + 37x - 17x - x = (25+37-17-1)x = 44x$$
4. Упростите выражение и вычислите его значение:
1) $$37a + 83a$$, если $$a = 8$$
$$37a + 83a = (37+83)a = 120a = 120 \cdot 8 = 960$$
2) $$82b - 28b$$, если $$b = 32$$
$$82b - 28b = (82-28)b = 54b = 54 \cdot 32 = 1728$$
3) $$33c - 6c - 7c$$, если $$c = 549$$
$$33c - 6c - 7c = (33-6-7)c = 20c = 20 \cdot 549 = 10980$$
4) $$17x - 8x + 31x - 18$$, если $$x = 312$$
$$17x - 8x + 31x - 18 = (17-8+31)x - 18 = 40x - 18 = 40 \cdot 312 - 18 = 12480 - 18 = 12462$$