Q6.
The slope-intercept form: y = mx + b
m - slope
b - y-intercept
We have: slope m = 3, y-intercept (0, 4) → b= 4
Answer: y = 3x + 4
Q7.
2x + 4y = 4 |subtract 2x from both sides
4y = -2x + 4 |divide both sides by 4
y = -0.5x + 1
Only second graph has y-intercept = 1.
Answer: The second graph.
Q8.
The point-slope form:

We have

Substitute:

Answer: The first equation.
Q9.
It's a vertical line. The equation of a vertical line is x = a, where a is any real number.
Answer: x = -4