Answer:
the distance of the 3rd car from the 7th car is
217 inch
Answer:
![\boxed{ \bold{ \huge{ \boxed{ \sf{x = 0.875}}}}}](https://tex.z-dn.net/?f=%20%5Cboxed%7B%20%5Cbold%7B%20%5Chuge%7B%20%5Cboxed%7B%20%20%5Csf%7Bx%20%3D%200.875%7D%7D%7D%7D%7D)
Step-by-step explanation:
![\sf{3[ x + 3(4x - 5)] = 15x - 24}](https://tex.z-dn.net/?f=%20%5Csf%7B3%5B%20x%20%2B%203%284x%20-%205%29%5D%20%20%3D%2015x%20-%2024%7D)
Distribute 3 through the parentheses
⇒![\sf{3[ x + 12x - 15 ] = 15x - 24}](https://tex.z-dn.net/?f=%20%5Csf%7B3%5B%20x%20%2B%2012x%20-%2015%20%5D%20%20%3D%2015x%20-%2024%7D)
Collect like terms : 12x and x
⇒![\sf{3[ 13x - 15 ] = 15x - 24}](https://tex.z-dn.net/?f=%20%5Csf%7B3%5B%2013x%20-%2015%20%5D%20%20%3D%2015x%20-%2024%7D)
Distribute 3 through the parentheses
⇒![\sf{39x - 45 = 15x - 24}](https://tex.z-dn.net/?f=%20%5Csf%7B39x%20-%2045%20%3D%2015x%20-%2024%7D)
Move 15x to left hand side and change it's sign
Similarly, move 45 to right hand side and change it's sign
⇒![\sf{39x - 15x = - 24 + 45}](https://tex.z-dn.net/?f=%20%5Csf%7B39x%20-%2015x%20%3D%20%20-%2024%20%2B%2045%7D)
Collect like terms
⇒![\sf{24x = - 24 + 45}](https://tex.z-dn.net/?f=%20%5Csf%7B24x%20%3D%20%20-%2024%20%2B%2045%7D)
Calculate
⇒![\sf{24x = 21}](https://tex.z-dn.net/?f=%20%5Csf%7B24x%20%3D%2021%7D)
Divide both sides of the equation by 24
⇒![\sf{ \frac{24x}{24} = \frac{21}{24}}](https://tex.z-dn.net/?f=%20%5Csf%7B%20%5Cfrac%7B24x%7D%7B24%7D%20%20%3D%20%20%5Cfrac%7B21%7D%7B24%7D%7D%20)
Calculate
⇒![\sf{x = 0.875}](https://tex.z-dn.net/?f=%20%5Csf%7Bx%20%3D%200.875%7D)
Hope I helped!
Best regards! :D