75+ 15x ≥ 140
⇒ 15x ≥ 140-75
⇒ 15x ≥ 65
⇒ x ≥ 65/15
⇒ x ≥ 13/3
⇒ x ≥ 4 1/3
Final answer: x ≥ 4 1/3~
As function is = 4x
so
4x=-x+5
5x=5
x=1
we have

Solve for c--------> that means that clear variable c
so
Divide by
both sides

Adds
both sides

Multiply by
both sides
![a[(R/5)+0.3]=c](https://tex.z-dn.net/?f=a%5B%28R%2F5%29%2B0.3%5D%3Dc)
so
![c=a[(R/5)+0.3]](https://tex.z-dn.net/?f=c%3Da%5B%28R%2F5%29%2B0.3%5D)
therefore
<u>the answer is</u>
![c=a[(R/5)+0.3]](https://tex.z-dn.net/?f=c%3Da%5B%28R%2F5%29%2B0.3%5D)