Answer and Step-by-step explanation:
The signs didn't really "swap". Instead, the whole function was divided by -1, or we could say the function was divided by -3. That would turn:
-18x² - 15x + 3 = 0
into
(-18 / -3)x² - (15 / -3)x + (3 / -3) = 0
6x² + 5x - 1 = 0
And that gives the "swapped signs".
Answer:

Step-by-step explanation:
Distribute the 5 into the parentheses (multiply them both by 5)

Subtract the 6.5 from -25.

Divide -31.5 by 15.5.

Answer:
Each shelf holds 30 inches of filling.
Step-by-step explanation:
Divide 180 inches of filling by the six shelves and you get 30 inches of filling per shelf
You are welcome
Answer:
-10
Step-by-step explanation:
-4 between each number
Answer: x=10
Step-by-step explanation:
=
=
5(x+5)=3(3x-5)
5x+25=9x-15
25=4x-15
4x=40
x=10