Answer:
25x^2 +40x+16
Step-by-step explanation:
(5x + 4)²
(5x+4)(5x+4)
FOIL
first 5x*5x = 25x^2
outer 5x*4 = 20x
inner 4*5x = 20x
last = 4*4 = 16
Add them together
25x^2 +20x+20x+16
Combine like terms
25x^2 +40x+16
Answer:
[tex] {(5x + 4)}^{2} \\ = {(5x)}^{2} + 2 \times 4 \times 5x + {4}^{2} \\ = 25 {x}^{2} + 40x + 16 \\ thank \: you[/tex]