Answer:
Ball hits the ground after 4.5 sec
Step-by-step explanation:
Let a -1, so that the leading coefficient is positive
So our quadratic is

The key coefficients of two binomial variables can be 1 and 16, or 2 and 8, or 4 and 4, for the leading coefficient of 16.
Yet they can't actually be 4 and 4 because the linear (x) term coefficient has to be a multiple of 4, which it isn't and leading coefficients 1 and 16 on the binomial factors is not likely.
So, 2 and 8 taken as the leading coefficients of two binomial factors.
For constant 405, possible factorizations are 

Taking first factor, thus we find negative value for given time t. But second time equivalent to zero gives the value of 4.5 for t
Thus ball hits the ground after 4.5 sec
.
Answer:
x = 0.5
y = -1/4 or -0.25
Step-by-step explanation:
x + 6y = 2
3x + 2y = 10
Multiply a number by any of the equations to get numbers of the same variable
3x + 18y = 6
3x + 2y = 10
3x - 3x = 0
NB: subtract evenly if u subtract down from top make sure u subtract down from top throughout
16y = -4
16y/16 = -4/16
y = -1/4 or -0.25
to find the x value, any where you see y u put in the y value(-0.25)
So u'll pick just one of the equations above
x + 6(0.25) = 2
x + 1.5 = 2
x = 1.5 + 2
x = 0.5
Answer: IXL
Step-by-step explanation:
Gretchen will earn $48 from mowing in 4 hours
Data
- Amount earned on each lawn = $12
- Number of hours mowing = 4 hours
<h3>What is Rate</h3>
This is the measure of one unit against another unit. An example of this is speed which is the rate of distance covered to time.
In this case, she mows 1 lawn in each hour and earns $12 on each.
To calculate for 4 hours

She earns $48 from mowing 4 lawns
learn more on rates here;
brainly.com/question/8728504
Answer:
<h2>B. The amount of fuel used was lowest at speeds around 60km/h.</h2>
Step-by-step explanation:
The decreasing part is from (20,13) to (60,6), which gives an average rate of

Then, we have an increasing part from (60,6) to (120,10), which gives an average rate of

Basically, at 60 km/h the fuel used was 6 liters per 100 kilometers. Notice that the other velocities make the car to use more liters per kilometers.
Therefore, the amount of fuel used was lowest at speeds around 60 km/h.