Answer:

Step-by-step explanation:
<u><em>The picture of the question in the attached figure</em></u>
we know that
The perimeter of a triangle is the sum of the length of their three sides
so

where
a,b,c are the length sides of the triangle
In this problem we have

substitute and solve for the missing length

Answer:
(7x+4) and (4x)
Step-by-step explanation:
The two expressions are (7x+4) and (4x)
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.