А) у = 4х + 9 и у = 6х - 54x + 9 = 6x - 54x - 6x = -5 - 9-2x = -14x = 7y = 4 · 7 + 9 = 37y = 6 · 7 - 5 = 37(7 ; 37) б) y = 16x - 7 и y = 21x + 816x - 7 = 21x + 816x - 21x = 8 + 7-5x = 15x = -3y = 16 · (-3) - 7 = - 48 - 7 = -55y = 21 · (-3) + 8 = - 63 + 8 = -55(-3 ; -55) в) y = 10x - 7 и y=510x - 7 = 510x = 12x = 1,2y = 10 · 1,2 - 7 = 12 - 7 = 5y = 5(1,2 ; 5) г) y = 0,1x и y = 140,1x = 14x = 140y = 0,1 · 140 = 14y = 14(140 ; 14)