Let's fill in the blanks step-by-step:
1. In direct proportion, [tex]\( \frac{a_1}{b_1} \)[/tex] is equal to [tex]\( \frac{a_2}{b_2} \)[/tex].
- Explanation: When two quantities are in direct proportion, the ratio of the first pair of quantities is equal to the ratio of the second pair of quantities.
2. If the distance remains constant, then speed and time vary inversely.
- Explanation: When distance is constant, speed and time have an inverse relationship. If the speed increases, the time taken decreases, and vice versa.
3. The diameter and circumference of a circle vary directly with each other.
- Explanation: The diameter and circumference of a circle have a direct relationship. If one increases, the other also increases proportionally.
So, the complete filled-in answer would be:
1. In direct proportion, [tex]\( \frac{a_1}{b_1} = \frac{a_2}{b_2} \)[/tex].
2. If the distance remains constant, then speed and time vary inversely.
3. The diameter and circumference of a circle vary directly with each other.
