Answer:
-20x^2 + 53x -18
Explanation:
FOIL
First terms
Outer terms
Inner terms
Last terms
So lets do our F:
5x * -4x = -20x^2
Now lets do our O:
5x * 9 = 45x
Now lets do our I:
-2 * -4x = 8x
Now lets do our L:
-2 * 9 = -18
Lets put all those together:
-20x^2 + 45x + 8x - 18
Combine like terms:
-20x^2 + 53x -18
Use distributive property: (a + b)(c + d) = ac + ad + bc + bd.
[tex](5x-2)(-4x+9)=(5x)(-4x)+(5x)(9)+(-2)(-4x)+(-2)(9)\\\\=-20x^2+45x+8x-18=\boxed{-20x^2+53x-18}[/tex]