№2. Упростить выражение. a) 5x² + (x + 1 + x²); b) 0,5a + (a + a³ + 5); c) 7m - (3m + mn + n); d) 5p² - (d+p2-3pq).

a) $$5x^2 + (x + 1 + x^2) = 5x^2 + x + 1 + x^2 = 6x^2 + x + 1$$ b) $$0,5a + (a + a^3 + 5) = 0,5a + a + a^3 + 5 = a^3 + 1,5a + 5$$ c) $$7m - (3m + mn + n) = 7m - 3m - mn - n = 4m - mn - n$$ d) $$5p^2 - (d + p^2 - 3pq) = 5p^2 - d - p^2 + 3pq = 4p^2 - d + 3pq$$ Ответ: a) $$6x^2 + x + 1$$; b) $$a^3 + 1,5a + 5$$; c) $$4m - mn - n$$; d) $$4p^2 - d + 3pq$$