Melinda derives the quadratic formula from the following equation, and her four steps are shown below.

y=2x+15

where y=Value of coin

x=Age in years

Value of coin after 19 years=2*19+15

=$53

Therefore, Value after 19 years=$53

F=ma

where F=force

m=mass

a=acceleration

Here,

F=4300

a=3.3m/s2

m=F/a

    =4300/3.3

    =1303.03kg

Approximately it is aqual to 1300kg

The answer is in the image 

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales

Here,

tip=18%of $32

tip=(18/100)*32

=0.18*32

=$5.76

Total payment=32+5.76=$37.76

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales

The answer is in the image 

Given height of gymnasium is 5/6 height of 30 foot ball

therefore height of gymnasium=5/6 * 30

=25 feet

The solution is given below

There are 6 outcomes 1,2,3,4,5,6

Total outcomes = 6

Outcomes when rolling a number is 4 or less = 1,2,3,4

Total outcome when rolling a number is 4 or less=4

Probability = required outcome/total outcome

                 =4/6

                 =2/3

Therefore probability = 2/3