Answer:
a) t = 0.54 seconds
b) t = 8 seconds
Step-by-step explanation:
Given in the question the equation
h = 40t - 5t²
<em> where h is height in meters</em>
<em> t is time in seconds</em>
<em />
Time it took to reach 20 meters
20 = 40t - 5t²
-5t² + 40t - 20 = 0
by using quadratic formula for factorisation
<h3>t = (-b± √(b)² - 4(a)(c) ) / 2(a)</h3>
t = 0.54 (upward motion)
or
t = 7.46 (downward motion)
b) Time it took to reach the ground
at ground h = 0
So,
0 = 40t - 5t²
t(40 - 5t ) = 0
t = 0 (at starting point)
or
40 -5t = 0
5t = 40
t = 40 /5
t = 8 seconds
4a^2+7ab-b^2
Step-by-step explanation:
Add the first two equations together:
3a^2-ab-2b^2
+ 2a^2+5ab-3b^2
---------------------------
5a^2+4ab-5b^2
Subtract that answer from the remaining trinomial:
5a^2+4ab-5b^2
- a^2-3ab-4b^2
--------------------------
4a^2+7ab-b^2
Answer:
it's a black image theres no line
Answer:
y = 1/2x + 6
Step-by-step explanation:
1/2 is the slope and 6 is the y-intercept
