Условие:

Вычисли удобным способом.
87 * 64 + 87 * 36;
39 * 16 + 39 * 4;
96 * 77 − 96 * 76;
48 * 61 − 40 * 61;
24 * 49 + 24;
34 * 21 − 34.

87 * 64 + 87 * 36 = 87 * (64 + 36) = 87 * 100 = 8700;
39 * 16 + 39 * 4 = 39 * (16 + 4) = 39 * 20 = 780;
96 * 77 − 96 * 76 = 96 − (77 − 76) = 96 * 1 = 96;
48 * 61 − 40 * 61 = 61 * (48 − 40) = 61 * 8 = 488;
24 * 49 + 24 = 24 * 49 + 24 * 1 = 24 * (49 + 1) = 24 * (49 + 1) = 24 * 50 = 1200;
34 * 21 − 34 = 34 * 21 − 34 * 1 = 34 * (24 − 1) = 34 * 20 = 680.