Tolong dong yang yang nomor 1 essay

a)
(p,-2)
disubstitusi ke persamaan
y = 7x + 19
-2 = 7p + 19
7p = -21
p = -3

b)
(5,q)

6x - 5y = 60
6(5) - 5q = 60
5q = 30 - 60
5q = -30
q = -6

c)
(r, r-1)

2x + 3y - 32 = 0
2r + 3(r-1) = 32
5r - 3 = 32
5r = 35
r = 7