(6n + 7)² - (3n + 2)² = (36n² + 84n + 49) - (9n² + 12n + 4) =
= 36n² - 9n² + 84n - 12n + 49 - 4 = 27n² + 72n + 45 = 9(3n² + 8n + 5) =
= 9(3n + 5)(n + 1)
У = -2х + 3
k = -2
b = 3
k-b = -2-3 = -5
Решение
<span>(1/3)^(5-3x) = 9
3^(3x - 5) = 3</span>²
<span>3x - 5 = 2
3x = 2 + 5
3x = 7
x = 7/3
x = 2(1/3)
</span>
смотри запись решения внизу