Question

Diketahui...
(1 1/3) (1 2/3)
solusi dari sistem persamaan linear kuadrat tidak lengkap adalah berikut

ax + by = 7

4x kuadrat - aXY + Y kuadrat = 1

maka carilah

a. nilai a dan b

b. solusi lain pertidak samaan tersebut

Answer 1

Ax + by = 7 => x= 4/3, y = 5/3
4a/3 + 5b+3 = 7
4a + 5b = 21

4x² -axy+y² = 1
==> (2x-y)(2x-y) = 4x² -4xy +y² 
-a = -4
a= 4

4.4+5b = 21
16+5b=21
5b =5 , b=1 ==> 4x+y = 7
2x-y = 1 atau -1

Kasus I: 4x+y =7, 2x-y = 1
4x+y =7
2x-y =1
---------- +
6x = 8,  x = 4/3, y = 7 - 16/3 = 5/3 (dari soal)

Kasus II : 4x +y = 7, 2x-y= -1
4x+y = 7
2x-y = -1
-----------+
6x = 6, x = 1
y= 7-1.4 = 3

Hasil x dan y = (4/3, 5/3) dan (1, 3)