Diketahui a+b = 27 dan axb = 176. Nilai dari a² + b²=

b = 27 - a
a x (27 - a) = 176
27 a - a^2 = 176
a^2 -27a + 176 = 0
(a -  16) (a - 11) = 0 ====> a = 16 atau a = 11
maka b = 27 - 16 = 11 atau b = 27 - 11 = 16

a^2 + b^2 = 16^2 + 11^2 = 256 + 121 = 377

a² + b² = (a + b)² - 2axb
            = (27)² - 2(176)
            = 729 - 352
            = 377