At the time the rocket hits the ground h=0, given that h=-16t²+320t+32
when h=0, our equation will be:
-16t²+320t+32=0
solving the above by completing square method we proceed as follows;
-16t²+320t+32=0
divide though by -16 we get
t²-20t-2=0
t²-20t=2
but
c=(-b/2a)^2
c=(20/2)^2
c=100
hence:
t²-20t+100=100+2
(t-10)(t-10)=102
√(t-10)²=√102
t-10=√102
hence
t=10+/-√102
t~20.1 or -0.1
since it must have taken long, then the answer is 20.1 sec
Step-by-step explanation:
The line of best fit is y = 2.599x + 105.08. At x = 20, the estimated height is y = 157.06. The actual height is 160 cm, so the residual is:
160 cm − 157.06 cm = 2.94 cm
I'm horrible at this so I'm just guessing.
X is the variable and x means multiplication symbol.
X + (X x 3 - 1) + (X x 3 - 1) - 4) <span>≥ 45 is the answer I got.
The answer to that inequality would be
X </span><span>≥ 7 I think.</span>
So first you have to find the perfect square that matches up with x^2 + 6x
so half of 6, and square it. your perfect square is 9
x^2 + 6x + 9 = 7 + 9
then, condense the left side of the equation into a squared binomial:
(x + 3)^2 = 16
take the square root of both sides:
x + 3 = ± √16
therefore:
x + 3 = ± 4
x = - 3 ± 4
so your solution set is:
x = 1, -7
The total number of mattresses that are sold in a year = 1,330
Percentage of King size mattresses sold = 30% = 30/100 = 0.3
Next, we have to calculate the actual number sold by using the formula given below:
Number of king size mattresses sold = Total mattresses sold in a year * percentage of king size mattresses sold
Number of King Size mattresses sold = 1,330*0.3 = 399
Number of king size mattresses sold = 399