Спростiть вираз 2a(3a-5)-(a-3)(a-7)

Question

Спростiть вираз 2a(3a-5)-(a-3)(a-7)

Answer 1

2a(3a - 5) - (a - 3)(a - 7) = 6a² - 10a - a²+ 7a + 3a - 21 = 5a² - 21