(a-7)²-2(a-7)(a+7)+(a+3)²=а²-14а+49-2(a²-49)+ a²+6a+9=а²-14а+49-2а²+98+а²+6а+9=
= -8а+156=156-8а при а=1/4=0,25,имеем
156-8*1/4=156-2=154
(a - 7)² - 2(a - 7) (a + 7) + (a + 3)² = a² - 14a + 49 - 2(a² - 49) + a² + 6a + 9 = a² - 14a + 49 - 2a² + 98 + a² + 6a + 9 = -8a + 156 = 156 - 8a
156 - 8a = 156 - 8*(1/4) = 156 - 2 = 154
(a-7)²-2(a-7)(a+7)+(a+3)²=а²-14а+49-2(a²-49)+ a²+6a+9=а²-14а+49-2а²+98+а²+6а+9=
= -8а+156=156-8а при а=1/4=0,25,имеем
156-8*1/4=156-2=154
(a - 7)² - 2(a - 7) (a + 7) + (a + 3)² = a² - 14a + 49 - 2(a² - 49) + a² + 6a + 9 = a² - 14a + 49 - 2a² + 98 + a² + 6a + 9 = -8a + 156 = 156 - 8a
156 - 8a = 156 - 8*(1/4) = 156 - 2 = 154