6. original: $80.00
percent of markup: 25%

$100

Step-by-step explanation:

If the original price is $80 and the markup is 25% of that, then the final price is equal to the original price plus the markup, or:

$80(1.25)  = $100

the rocket cannot penetrate the ground, in a contextual sense, therefore the roots of this equation should be the domain of this function. i'll let you find the roots of this quadratic equation (hint: use the quadratic formula:  

1- c

2-a

step-by-step explanation:

mark brainliest!