It takes 6 seconds for it to hit the ground.
0 = -5x²+20x+60
We can solve this by factoring. First factor out the GCF, -5:
0 = -5(x²-4x-12)
Now we want factors of -12 that sum to -4. -6(2) = -12 an -6+2 = -4:
0 = -5(x-6)(x+2)
Using the zero product property, we know that either x-6=0 or x+2=0; this gives us the answers x=6 or x=-2. Since we cannot have negative time, x=6.
Here, I'll do the first one for you.
When they are talking about a number, use "x".
Since it says twice a number, you say 2x. Or 3x for three times the number
2x+12=3x-31
Then use algebra to find x. Get the numbers on one side and all the x's on the other.
2x+12+31=3x-31+31
2x+43-2x=3x-2x
x=43
Now do the rest on your own!
Answer: 20 weeks in 1 week
in 2 weeks 40
Step-by-step explanation:
This proves that the equation is true
