Do u have an attachment?? :)
Answer:

Step-by-step explanation:
Answer:
<h2>a) |-13 - (-4)|</h2>
Step-by-step explanation:
The formula of a distance between two points (numbers) A and B on the number line:
d = |B - A| = |A - B|
We have A = -13 and B = -4. Substitute:
d = |-13 - (-4)|
Suppose Alex has 3x stamps, Freddy has 5x stamps. After Freddy gives Alex 10 stamps, Alex has 3x+10 while Freddy has 5x-10
the new ratio is 7 to 9, so we have the equation: (3x+10)/(5x-10)=7/9
9(3x+10)=7(5x-10)
27x+90=35x-70
160=8x
x=20
So Alex has 3*20=60 stamps while Freddy has 5*20=100. Together they have 160