%5E2-a(5a-6)-%D0%BF%D1%80%D0%B8-a%3D-1%2F2.jpeg "(a-3)^2-a(5a-6) При A=-1/2")
Solving the Expression (a-3)^2 - a(5a-6) When a = -1/2
This problem involves simplifying an algebraic expression and then substituting a specific value for the variable. Let's break it down step-by-step:
1. Simplify the Expression:
- Expand the square: (a-3)^2 = (a-3)(a-3) = a^2 - 6a + 9
- Distribute the 'a': -a(5a-6) = -5a^2 + 6a
Now the expression becomes: a^2 - 6a + 9 - 5a^2 + 6a
- Combine like terms: -4a^2 + 9
2. Substitute a = -1/2:
- -4(-1/2)^2 + 9
- -4(1/4) + 9
- -1 + 9
- 8
Therefore, the value of the expression (a-3)^2 - a(5a-6) when a = -1/2 is 8.