Changing the x from positive to negative, reflects the graph over the Y-Axis.
Adding 7 to X shifts the graph horizontally 7 units to the right.
Kx^2-x-1=0
Kx^2-x=1
Kx^2=1+x
K=1+x/x^2
-2(b-1)=2(1+7b)
First, distribute; -2b+2=2+14b
Get the variables on one side; -2b+2=2+14b
-14b -14b
Get the constants on one side; -16b+2=2
-2 -2
Divide to find “b”; -16b/-16=0/-16
b=0
It takes 9 seconds to hit the ground.
Setting the equation equal to 0, we have:
0 = 144 + 128t - 16t²
Factoring out the GCF, we have
0 = 16(9 + 8t - t²)
Factoring out -1, we have:
0 = -16(-9 - 8t + t²)
In standard form, this is
-16(t² - 8t - 9) = 0
This is easily factorable; -9(1) = -9 and -9+1 = -8:
-16(t-9)(t+1) = 0
Using the zero product property, we know either t-9=0 or t+1=0; therefore t=9 or t=-1. Since negative time makes no sense, t=9.
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