(p+9)² - (r+5)² tolong dijawab sekarang harus dikumpulin

(p+9)² - (r+5)²
= (p²+18p+81)-(r²+10r+25)
=p²+18p-r²-10r+56

jalan panjang
(p+9)²=(p+9)(p+9)
masing masing dikali
= p²+9p+9p+81
=p²+18p+81

begitu juga (r+5)²
= (r+5)(r+5)
=r²+5r+5r+25
=r²+10r+25

digabung
(p²+18p+81)-(r²+10r+25)
buka kurung jadi
p²+18p+81-r²-10r-25
=p2+18p-r²-10r+81-25
=p²+18p-r²-10r+56