Answer:
<h3>5 seccs</h3>
Step-by-step explanation:
Given the modeled function of the height expressed as;
h(t)=-16t^2+64t+80
The ball hits the ground when h(t) = 0 (when the height is zero)
Substitute into the function and find t;
0 =-16t^2+64t+80
divide through by -16
0 = t²-4t-5
Factorize;
t²-4t-5 = 0
t²-5t+t-5 = 0
t(t-5)+1(t-5) = 0
(t+1)(t-5) = 0
t + 1 = 0 and t-5 = 0
t = -1 and t = 5
Time can't be negative
Hence it will take the ball 5secs before it hits the ground
Answer:
Option B,They are not valid because the student did not control all the variables that can affect plant growth
Step-by-step explanation:
In case of water applied to the plants - the student watered the plant to which he has spoken by hand and to the remaining plants to which he has not spoken, he watered them by using sprinkler.
Water is an essential factor that effects plant growth. This factor must have been controlled. However, the water was given to both the plants only the quantity of water given varies in the two cases. Hence, the claim of student is not valid.
Hence, option B is correct
Answer:
-17/4
Step-by-step explanation:
4x+6+3=-8
4x+9=-8
-9 -9
4x=-17
÷4 ÷4
X=-17⁄4
Step-by-step explanation:
first ..
subtract 2 on both sides 2-2...2-y
then you should have 1/2x =y-(-2) then divide
