She had spent $78 on books but idk what to do with the book mark cuz it ask for the total # of books not book marks
Answer:

Step-by-step explanation:
Given that 

Answer:
small dogs= 5
large dogs= 3
Step-by-step explanation:
Step one:
given data
let the number of small dogs be x
and the number of large dogs be y
Ryan earns $5 for each small dog he walks and $8 for each large dog he walks.
He walked 8 dogs and made a total of $49
so
5x+8y=49----------1
x+y=8---------------2
x=8-y
5(8-y)+8y=49
40-5y+8y=49
collect like terms
3y= 49-40
3y=9
divide both sides by 3
y=9/3
y=3
put y= 3 in eqn 2
x+3=8
x=8-3
x=5
Step-by-step explanation:
x = a + 7
y = b-a
To prove
x + y = b + 7.
- x+y= (a+7) + (b-a)
=a+7+b-a
=a-a+7+b
=0 + 7+b
= b+7
Proved ✅
2.2 with the decimal 2 repeating