To write the equation of a line with a given gradient (slope) and y-intercept, you can use the slope-intercept form of a line, which is:

$y = mx + c$

Where:

• $m$ is the gradient (slope) of the line.
• $c$ is the y-intercept (the point where the line crosses the y-axis).

Given:

• Gradient ($m$) = 3
• Y-intercept ($c$) = -4

Substituting these values into the slope-intercept form:

$y = 3x - 4$

So, the equation of the line is:

$y = 3x - 4$

Would you like more details on this, or do you have any questions?

Here are five related questions you might find interesting:

1. How do you find the equation of a line passing through two given points?
2. What is the equation of a line perpendicular to $y = 3x - 4$?
3. How do you determine if two lines are parallel?
4. How do you convert the slope-intercept form of a line to the point-slope form?
5. How do you find the x-intercept of the line $y = 3x - 4$?

Tip: When writing the equation of a line, always start by identifying the slope and y-intercept, as these are the key components.