Question:
The relationship between t and r is expressed by the equation 2t+3r+6 = 0. If r increases by 4, which of the following statements about t must be true?
Answer:
The value of t is reduced by 6 when the value of r is increased by 4
Explanation:
Given
![2t + 3r + 6 = 0](https://img.qammunity.org/2021/formulas/mathematics/college/la1b14zgdn67m9jba0j2vk9vq6ohl1essh.png)
Required
What happens when r is increased by 4
-------- Equation 1
Subtract 2t from both sides
![2t + 3r + 6 - 2t = 0 - 2t](https://img.qammunity.org/2021/formulas/mathematics/college/4f2qjdyslplkl8wihft66n4v14hibx56ne.png)
--- Equation 2
When r is increased by 4, equation 1 becomes
Note that the increment of r also affects the value of t; hence, the new value of t is represented by T
Open bracket
Rearrange
![2T + 3r+6 +12 = 0](https://img.qammunity.org/2021/formulas/mathematics/college/fpn81yffyodbawmdpiyqs8rpm1qtif0a70.png)
Substitutr -2t for 3r + 6 [From equation 2]
![2T -2t +12 = 0](https://img.qammunity.org/2021/formulas/mathematics/college/t192nj7akvbkyl4464mvgjvu20cz3cjhwk.png)
Make T the subject of formula
![2T = 2t - 12](https://img.qammunity.org/2021/formulas/mathematics/college/5xcj5l4244zxdqovvuuupq2iyhnc7r1dqg.png)
Divide both sides by 2
![(2T)/(2) = (2t - 12)/(2)](https://img.qammunity.org/2021/formulas/mathematics/college/5bjbrm3uw09swlfdmsn5f3fh10bz7ebs0y.png)
![T = t - 6](https://img.qammunity.org/2021/formulas/mathematics/college/67qfj235v918e34t9kegoacsppb4chmqv2.png)
This means that the value of t is reduced by 6 when the value of r is increased by 4