bila hasil dari 3(5x-1per 6)pangkat 2=ax pangkat 2+bx+c,maka nilai a+b+12c=

ax² + bx + c = 3(5x - 1/6)(5x - 1/6)
ax² + bx + c = 3(25x² - 10x/6 + 1/36)
ax² + bx + c = 75x² -30x/6 + 3/36
ax² + bx + c = 75x² -5x + 1/12

a → 75
b → -5
c → 1/12

jadi,
a + b + 12 c = 75 + (-5) + 12(1/12)
a + b + 12 c = 75 - 5 + 1
a + b + 12 c = 69

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