Respuesta :
Answer:
20x²+180x + 405
Step-by-step explanation:
Follow PEMDAS to know what you do first
square (2x + 9) by foiling
(2x+9) (2x + 9)
= 4x²+ 36x + 81
Multiply by 5
20x²+180x + 405
Answer:
20x^2 + 180x +405
Step-by-step explanation:
5(2x+9)²
5 ( 2x+9) (2x+9)
FOIL
first
2x*2x = 4x^2
outer: 2x*9 = 18x
inner 2x*9 = 18x
last : 9*9 = 81
Add these together : 4x^2 + 18x+18x +81 = 4x^2+36x+81
5( 4x^2+36x+81 )
20x^2 + 180x +405