Verified answer

а) у = 4х + 9 и у = 6х - 5

4x + 9 = 6x - 5

4x - 6x = -5 - 9

-2x = -14

x = 7

y = 4 · 7 + 9 = 37

y = 6 · 7 - 5 = 37

(7 ; 37)

б) y = 16x - 7 и y = 21x + 8

16x - 7 = 21x + 8

16x - 21x = 8 + 7

-5x = 15

x = -3

y = 16 · (-3) - 7 = - 48 - 7 = -55

y = 21 · (-3) + 8 = - 63 + 8 = -55

(-3 ; -55)

в) y = 10x - 7 и y=5

10x - 7 = 5

10x = 12

x = 1,2

y = 10 · 1,2 - 7 = 12 - 7 = 5

y = 5

(1,2 ; 5)

г) y = 0,1x и y = 14

0,1x = 14

x = 140

y = 0,1 · 140 = 14

y = 14

(140 ; 14)