Answer:
Step-by-step explanation:
"A mathematical model is a description of a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used in the natural sciences (such as physics, biology, earth science, chemistry) and engineering disciplines (such as computer science, electrical engineering), as well as in the social sciences (such as economics, psychology, sociology, political science).
A model may help to explain a system and to study the effects of different components, and to make predictions about behavior."
To make t the subject is basically isolating t
S = at + bt
We see on the right side that t is common, so we factor it out.
S = t(a + b)
Divide by (a+b) to isolate t
a + b and a + b cancels out
We are left with the answer:
t = 
Basically there are 3 addition properties and they are associative property, identity property, and commutative property.
Commutative property is just changing the order of the addends. Example: 26+19+34+21= 21+34+19+26
Identity Property is just adding a 0 to the number that doesnt change anything. Example: 26+19+34+21 +0 = 100
Associative property is just changing the grouping of the addends. Example: (26+19) + (34+21)
