Answer:
a set of two or more equations, each containing two or more variables whose values can simultaneously satisfy both or all the equations in the set, the number of variables being equal to or less than the number of equations in the set.
Step-by-step explanation:
It works because of two properties of equations: Multiplying (or dividing) the expression on each side by the same number does not alter the equation. Adding two equations produces another valid equation: e.g. 2x = x + 10 (x = 10) and x − 3 = 7 (x also = 10).
The answer to 8a. is 17, the answer to 8b. is 3.9, the answer to 8c. is 1 / 2, the answer to 8d. is 7 7 / 8, the answer to 9a. is commutative property, the answer to 9b. is multiplicative identity property, the answer to 9c. is associative property, and the answer to 9d. is additive inverse property.
Regarding the whole "explain using mental math" thing, I pretty much just used the fact that 8a. and 8b. both had the same number of decimal places. For 8c., I just made each number have a denominator of 10. And last, for 8d., all of the denominators were already the same, which made it pretty easy. I apologize for this section of my answer being so informal lol, I haven't had to do these kinds of problems in like 5 years <span />
Answer:
thats correct
Step-by-step explanation:
Answer:
A) 48 in : initial height of the water
B) 40.5 in : height of the water after 5 days
C) 32 days
D) Yes, should be restricted.
Domain: 0 ≤ d ≤ 32
Step-by-step explanation:

A)

48 in is the initial height of the water
B)

40.5 in is the height of the water after 5 days
C) when the pool is empty, h = 0.
So set the equation to zero and solve for d.

D) Yes, the domain should be restricted because when d > 32, h < 0 and the height of the water in the pool cannot be negative
Domain: 0 ≤ d ≤ 32