(8x+5)X(5x-2) (Luas persegi panjang dan kelilingnya?)

Luas = (8x+5) (5x-2)
= (8x 5x) + (8x (-2)) + (5 5x) + (5 (-2))
= 40[tex] x^{2} [/tex] - 16x + 25x - 10
= 40[tex] x^{2} [/tex] + 9x - 10

Keliling = 2(8x+5) + 2(5x-2)
= 16x + 10 + 10x - 4
= 16x + 10x + 10 - 4
= 26x + 6

(maaf kalau salah)