Answer:
a = 15
Step-by-step explanation:
A proportion looks like this:

It means that the quantity a,b,c and d are in the same proportion: the ratio between a and b is the same ratio between c and d.
They are particularly useful in situation when you have an example given, and you want to extrapolate the relationship for another couple.
For example, you can think of the following problem: "Five apples cost 2 dollars. How much will 8 apples cost?"
You can build the proportion

And then solve it for x:

Answer:
1) 10
2) 16
Step-by-step explanation:
1) 2x+15=37-2
2x+15=35
2x=35-15
2x=20
2 2
x=10
2)10x-8=9x+8
10x-9x=8+8
x=16
Hope this helps ❤
Answer:
13
Step-by-step explanation:
Given:
- Square stickers that were 3/4 in long
- The spine is 10 and 1/2 in long
If she laid the stickers side by side without gaps or overlaps so the number of sticker to cover the length of the spine:

10 :
≈13
She needs 13 stickers cover the length of the spine
Answer:
10
Step-by-step explanation: