Question

(2a-5)^2+(1-3a)(3-2a)-7a​

Answer 1

Решение:

​(2a - 5)² + (1 - 3a) * (3-2a) - 7a = 4a² - 20a + 25 + 3 - 2a - 9a + 6a² - 7a = 10a²  - 38a + 28

Answer 2

To simplify the expression, let's expand each term and then combine like terms:

1. Expand (2a-5)^2: (2a - 5)^2 = (2a - 5)(2a - 5) = 4a^2 - 10a - 10a + 25 = 4a^2 - 20a + 25

2. Expand (1 - 3a)(3 - 2a): (1 - 3a)(3 - 2a) = 1 * 3 - 1 * 2a - 3a * 3 + (-3a) * (-2a) = 3 - 2a - 9a + 6a^2 = 6a^2 - 11a + 3

Now, the simplified expression is the sum of the expanded terms: (2a - 5)^2 + (1 - 3a)(3 - 2a) - 7a = (4a^2 - 20a + 25) + (6a^2 - 11a + 3) - 7a

Combine like terms: = 4a^2 - 20a + 25 + 6a^2 - 11a + 3 - 7a

Now, add the coefficients of the same powers of 'a': = (4a^2 + 6a^2) - 20a - 11a - 7a + 25 + 3

= 10a^2 - 38a + 28

So, the simplified expression is: 10a^2 - 38a + 28.