Answer:
[tex]-8x^2 - 4x + 29 \\[/tex]
Step-by-step explanation:
Second expression evaluates to:
[tex](5 + x -2x)^2 = (5 -x)^2 = (-x+5)^2 = x^2 + 2(-x)(5) +5^2 = x^2 -10x + 25[/tex] (1)
For (1) We are using the rule [tex](a+b)^2 = a^2 +2ab + b^2\\\\[/tex]
Here [tex]a = -x, b = 5\\\\[/tex]
First expression evaluates to
[tex](3x)^2 -6x - 4 = 9x^2 -6x -4[/tex] (2)
Subtract (2) from (1)
[tex]x^2 - 10x +25 - (9x^2 -6x -4) = x^2-9x^2 -10x - (-6x) +25 -(-4)\\\\= -8x^2 - 4x + 29 \\[/tex]
