First of all, Elena is kinda dumb why put brochures on only 80%? Nevertheless, 400 letters will not contain a brochure. If you need an explanation just comment that you need one on this.
C . Parabola that opens to the left
Answer:c
Step-by-step explanation:i did it
Answer:

Step-by-step explanation:
The equation they are giving is:

Multiply both sides by 7 to get:

Subtract 4x from both sides to reach:

Therefore,
.
Hope this helps :)