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Translate A(1, 1) B(3, 1) C(1, 3) 2 right 1 up, then dilate by scale…

Step by step, with the reason for every step · Two moves in a row · Geometry

Step by step

The question

Question: translate the shape A(1, 1), B(3, 1) and C(1, 3) right 2, up 1, then dilate it scale factor 2.

A(1, 1), B(3, 1) and C(1, 3)
= translate right 2, up 1,
= then dilate scale factor 2

1 Draw the shape

Put the points on the grid and join them.

2 First: translate

Translation right 2, up 1: right 2 adds 2 to x, up 1 adds 1 to y.

The rule is: (x, y) goes to (x + 2, y + 1).

(x, y) → (x + 2, y + 1)

A(1, 1) goes to A'(3, 2).

A(1, 1) → A'(3, 2)

B(3, 1) goes to B'(5, 2).

B(3, 1) → B'(5, 2)

C(1, 3) goes to C'(3, 4).

C(1, 3) → C'(3, 4)

Join them.

This is the first image.

3 Then: dilate by scale factor 2

Dilation scale factor 2: both numbers are multiplied by 2.

The rule is: (x, y) goes to (2x, 2y).

(x, y) → (2x, 2y)

A'(3, 2) goes to A''(6, 4).

A'(3, 2) → A''(6, 4)

Careful!

The second move starts from the new points A', B' and C'.

Not from the first shape.

Careful: start from A', not from A

B'(5, 2) goes to B''(10, 4).

B'(5, 2) → B''(10, 4)

C'(3, 4) goes to C''(6, 8).

C'(3, 4) → C''(6, 8)

Join them.

This is the final image.

So the final image is A''(6, 4), B''(10, 4) and C''(6, 8).

A''(6, 4), B''(10, 4) and C''(6, 8)

4 Check

Let's check in one go.

Put the first rule's answer (x + 2, y + 1) into the second rule.

We get (2x + 4, 2y + 2).

(x, y) → (x + 2, y + 1) → (2x + 4, 2y + 2)

A goes straight to (6, 4).

That is A''.

Right!

A(1, 1) → A''(6, 4)

Let's look back.

First: draw the shape.

Then: translate right 2, up 1.

Then: dilate by scale factor 2.

Last: check.

Answer
A''(6, 4), B''(10, 4) and C''(6, 8)

Your turn

Try this one yourself, then check:

A(1, 2) B(3, 2) C(1, 4): translate right 1, up 1, then dilate scale factor 2
Show the answer
A''(4, 6), B''(8, 6) and C''(4, 10)

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