Answer:
Step-by-step explanation:
Ex 1 : B
Ex 2; B
Ex 3; D
Answer:
a.
b. 20
c.
Step-by-step explanation:
a. 58 of 78 are from state A
b. 78 minus 58 equals 20
c. 20 of 78 are found in states other than state A
Letters represent variables. A variable can be used as a replacement for a number that we do not yet know. A variable can represent a number.