Who is good at math??

Explanation:

The x terms are 8x and -4x. They combine to 8x-4x = 4x

The z terms are 5z and 3z. They combine to 5z+3z = 8z

The 6 doesn't have anything to pair with it, so it just stays as is.

That's how we get to 4x+8z+6 as the answer.

Here's one way to think about combining like terms.

Let's say x represents a box

1x = 1 box

2x = 2 boxes

3x = 3 boxes

and so on

So saying 8x means we have 8 boxes and -4x means we take 4 boxes away

(8 boxes) take away (4 boxes) = 4 boxes left

In shorthand we'd say,

8x - 4x = 4x

Similarly, we could have

1z = 1 zebra

2z = 2 zebras

etc.

Writing 5z+3z = 8z means we started with 5 zebras, added on 3 more, to get 8 total.

the image of (6, 9) under a dilation is (4, 6). the scale factor is

x/3-10=8

x/3=18

x=48