Which one of the following statements expresses a true proportion?
a. 2: 1 = 1: 2
b. 7: 9 = 8: 9
c. 54: 9 = 6: 3
d. 3: 4 = 9: 12
explain

The answer is D because if I cut a pie into 4 pieces and ate 3, it's the same amount as if I cut a pie into 12 pieces and ate 9. To realize this, 3x3 is 9 and 4x3 is 12 therefore 3:4 = 9:12

All points to the left of zero on a horizontal number line are negative. a number line is a picture of a graduated straight line that serves as abstraction for real numbers. this number line can be extended to the left to represent numbers which are smaller than 0. such numbers are called negative numbersmark me brainliest