tolong bantu plisss, makasih :))

a. A ( -8 , a)
y = - 1/4x + 15
y =- 1/4 x (-8) + 15
= 2+15 =17
a = 17

b. B (b, 5)
4x - 3y + 7 = 0
4x - 3 x 5 + 7 = 0
4x - 15 + 7 = 0
4x -9 = 0
4x = 9
x = 2,25

b = 2,25


kalo ga salah gini