數學3題唔該><關於coordinate(20點)急!!!

1.
Equation of the graph : y = 4x - 3

When x = 2 and y = 4 :
L.S. = 4
R.S. = 4(2) - 3 = 5
L.S. ≠ R.S.
Hence, A(2, 4) does NOT lie on the graph of theequation y = 4x - 3

When x = 3 and y = 9 :
L.S. = 9
R.S. 4(3) - 3 = 9
L.S. = R.S.
Hence, B(3, 9) lies on the graph of the equation y = 4x- 3


2.
(a)
Equation of the graph : 2x - 5y = a

A(5, 0) lies on the graph.
Put x = 5 and y = 0 into the equation 2x - 5y = a :
2(5) - 5(0) = a
a = 10

(b)
Equation of the graph : 2x - 5y = 10
B(0, b) lies on the graph.
Put x = 0 and y = b into the equation 2x - 5y = 10 :
2(0) - 5(b) = 10
b = -2