7. Найдите значения выражений, используя распределительное свойство умножения. a) 78 ⋅ 35 + 22 ⋅ 35=(78+22) ⋅ 35 = б) 8 ⋅ 7 + 8 ⋅ 4 = в) 42 ⋅ 42 - 32 ⋅ 42 + 10 ⋅ 42 = г) 19 ⋅ 17 + 11 ⋅ 17 = д) 7 ⋅ 379 - 6 ⋅ 379 = е) 19 ⋅ 65 + 12 ⋅ 65 - 31 ⋅ 65 = ж) 16 ⋅ 83 + 19 ⋅ 83 - 32 ⋅ 83 = з) 927 ⋅ 18 - 927 ⋅ 17 = и) 36 ⋅ 52 + 54 ⋅ 52 =

Выполним вычисления, используя распределительное свойство умножения. а) $$78 \cdot 35 + 22 \cdot 35 = (78+22) \cdot 35 = 100 \cdot 35 = \textbf{3500}$$ б) $$8 \cdot 7 + 8 \cdot 4 = 8 \cdot (7 + 4) = 8 \cdot 11 = \textbf{88}$$ в) $$42 \cdot 42 - 32 \cdot 42 + 10 \cdot 42 = 42 \cdot (42 - 32 + 10) = 42 \cdot 20 = \textbf{840}$$ г) $$19 \cdot 17 + 11 \cdot 17 = 17 \cdot (19 + 11) = 17 \cdot 30 = \textbf{510}$$ д) $$7 \cdot 379 - 6 \cdot 379 = 379 \cdot (7 - 6) = 379 \cdot 1 = \textbf{379}$$ е) $$19 \cdot 65 + 12 \cdot 65 - 31 \cdot 65 = 65 \cdot (19 + 12 - 31) = 65 \cdot (31 - 31) = 65 \cdot 0 = \textbf{0}$$ ж) $$16 \cdot 83 + 19 \cdot 83 - 32 \cdot 83 = 83 \cdot (16 + 19 - 32) = 83 \cdot (35 - 32) = 83 \cdot 3 = \textbf{249}$$ з) $$927 \cdot 18 - 927 \cdot 17 = 927 \cdot (18 - 17) = 927 \cdot 1 = \textbf{927}$$ и) $$36 \cdot 52 + 54 \cdot 52 = 52 \cdot (36 + 54) = 52 \cdot 90 = \textbf{4680}$$