Try this inequality with 0 as the right side.
-x > 0
According to John, we multiply both sides by -1, and the inequality sign does not change direction, so we get this
x > 0
Let's use a number for x that makes the original inequality true.
Let x = -2.
-x > 0
-(-2) > 0
2 > 0
As you can see, -2 does work on the original equation.
Now let's try -2 in John's solution.
x > 0
-2 > 0 which is a false statement.
Now let's solve it again, but we will reverse the inequality symbol when we multiply both sides by -1.
-x > 0
x < 0
Try x = -2.
-2 < 0 which is true
Now it works.
John is incorrect.
If you multiply or divide an equation by a negative number, even if one of its sides is 0, you still must change the direction of the inequality symbol.
Is the equation supposed to be like this
(c o f)(5)?
Answer:
the answer is 3/28
Step-by-step explanation:
<span>1,2,4,53,106,212
-----------------------
</span>
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
