Question

tìm x , y biết

(2x + 1)(y - 3) = 10

(3x + 2)(y - 5) = 60

Answer 1

(2x + 1)(y - 3) = 10

TH1 : 2x + 1 = 1 => 2x = 0 => x = 0

          y - 3 = 10 => y = 13

TH2 : 2x + 1 = 10 => 2x = 9 => x = 4,5

          y - 3 = 1 => y = 4

TH3 : 2x + 1 = 2 => 2x = 1 => x = 0,5

          y - 3 = 5 => y = 8

TH4 : 2x + 1 = 5 => 2x = 4 => x = 2

          y - 3 = 2 => y = 5

TH5 : 2x + 1 = -1 => 2x = -2 => x = -1

          y - 3 = -10 => y = -7

TH6 : 2x + 1 = -10 => 2x = -11 => x = -11/2

          y - 3 = -1 => y = 2 

TH7 : 2x + 1 = -2 => 2x = -3 => x = -3/2

          y - 3 = -5 => y = -2

TH8 : 2x + 1 = -5 => 2x = -6 => x = -3

          y - 3 = -2 => y = 1