Straight lines
Slope, intercepts, and parallel and perpendicular lines.
Learn with Kutty
Go one screen at a time. Press Next when you are ready. Tap 🔊 Read to me to listen.
The slope tells how steep a line is: up ÷ across.
Look: Across 1, up 2: slope 2. It crosses the y-axis at 1.
✏️ Your turn!
Type your answer and press Check. Kutty will tell you if it is right.
1Slope through (2, 3) and (6, 11)?
2Slope and crossing point of y = 3x − 4?
3Are y = 4x + 1 and y = 4x − 5 parallel?
! Careful!
✗Slope = across ÷ up.
✓Slope = up ÷ across.
✗Perpendicular slope of 2 is −2.
✓Flip and change sign: −½.
See the whole lesson on one page
The slope tells how steep a line is: up ÷ across.
In y = mx + c, m is the slope and c is where the line crosses the y-axis. Parallel lines have the same slope.
Think of it like thisA road that goes up 2 m for every 1 m forward is steep (slope 2). One that goes up 1 m every 10 m is gentle (slope 0.1).
- Slope
- Up ÷ across.
Solved together
Find the line through A(1, 2) and B(4, 8).
Up from A to B: 8 − 2 = 6. Across: 4 − 1 = 3.
slope = 6 ÷ 3 = 2y = 2x + c. Put in A(1, 2) to find c.
2 = 2 × 1 + cc = 0
AnswerThe line is y = 2x.
Now practise it
Kanakku makes new questions on straight lines every time. It shows the working and gives a hint when you are stuck.