Answer:
a) b = -5
b) slope = 3/2
Explanation:
a) The equation of a line is given as y = mx + b, where m is the slope of the line and b is the intercept on the y axis.
Given that y = 3x + b and it passes through the point (2, 1). Hence when x = 2, y = 1. Therefore, substituting for x and y:
1 = 3(2) + b
1 = 6 + b
b = 1 - 6
b = -5
b) The equation of a line passing through two points (
) and
is given by:

The equation of the line passing through the two points (0,3) and (4,9) is:

Comparing y = (3/2)x + 3 with y = mx + b, the slope (m) is 3/2
Answer:
The quantity of electrons that flows past a given point is 3.0 C.
Explanation:
An electric current (I) is the ratio of the quantity of charges (Q) that flows through a point to the time taken (t).
i.e I = 
It is measured in Ampere's by the use of an ammeter in the laboratory. The quantity of charge that flow through a given point is measured in Coulombs, while time is measured in seconds.
Given that; I = 1.5A and t = 2s, find Q.
Q = It
= 1.5 × 2
= 3.0 C
The quantity of electrons that flows past a given point is 3.0 C.
<span>Energy of an electromagnetic wave depends on it's "Frequency"
Hope this helps!</span>