Answer: 15.7 (1 decimal place)
Step-by-step explanation:
The formula for the circumference of a circle is d(diameter) x π(pi).
The diameter of this is 5 so you would do 5xπ=15.7 (1 decimal place)
For this case we have the following system of equations:

We solve by the substitution method:
We substitute the first equation in the second equation:

We apply distributive property considering that 

We subtract 69 from both sides of the equation:

We divide by 8 on both sides of the equation:

We look for the value of the variable y:

Thus, the solution of the system is 
Answer:

Answer 28.
Possible values for the three factors of -3
- 1, -1 and 3
- -1.5, 1 and 2
- 1.5, -1 and 2
- 1.5, 1 and -2
Answer 29.
The product of two nonzero integers will be less than or equal to both of the integers if they are multiplied by number itself and one or by number itself and one with negative sign.
Answer 30.
The sign of the product of three integers with the same sign will be positive or negative. If odd number of same sign is multiplied, the product will be of that sign.
(+) (+) (+) = (+)
(-) (-) (-) = (-)
(1073 + 1108 + x) / 3 = 1000
(2181 + x) / 3 = 1000 ....multiply both sides by 3
2181 + x = 1000 * 3
2181 + x = 3000
x = 3000 - 2181
x = 819 <== they would need to earn $ 819 on Sunday