I believe the answer is 47.
The value of 7 can be wrote as
7,000 or seven thousand
Problem 4-25
a. ii - Relation: When the latitude increases, the temperature decreases.
b. iv - Relation: all cars regardless of the weight goes at the same speed.
c. iii - Relation: No relationship
d. i - Relation: People with more expensive homes have more expensive cars.
System of Equations Part
You can plug these (x,y) values in one of the equations to see if it is true.
a. (1,2)
b. (0,-4)
c. (3,7)