Given: h(t) = 25 - a·t²
h(0.5) = 21
Find: t such that h(t) = 0
Solution: h(0.5) = 25 - a·0.5² = 21
25 - 21 = a/4
4·4 = a = 16
Then
h(t) = 25 - 16t²
We want h(t) = 0, so
0 = 25 - 16t²
16t² = 25
t² = 25/16 = (5/4)²
t = 5/4 = 1.25
It takes 1.25 seconds for the entire 25 ft drop.
Step 1 : Simplify both sides
-5(6a+21)=-15
(-5)(6a)+(-5)(21)=-15
-30a-105=-15
Step 2 : Add 105 to both sides
-30a-105+105=-15+105
-30a=90
Step 3 : Divide both sides by -30
-30a=90
—————
-30 -30
a = -3
Perpendicular lines have slopes that multiply to -1
get into y=mx+b form
minus 15x both sides and divide by -5
y=3x-7/5
slope is 3
3 times what=-1?
what=-1/3
so the slope is -1/3
so
y=-1/3x+b
we use the point (0,-4)
x=0 and y=-4
-4=-1/3(0)+b
-4=b
y=(-1/3)x-4 is da equation
Answer:

Step-by-step explanation:
From the question we are told that
System of equations given as
x₁ + 3x₂ + x₃ + x₄ = 3;
2x₁ - 2x₂ + x₃ + 2x₄ = 8;
x₁ - 5x₂ + x₄ = 5
Matrix form

Generally the echelon reduction is mathematically applied as

Add -2 times the 1st row to the 2nd row

Multiply the 2nd row by -1/8

Add -1 times the 2nd row to the 3rd row

Multiply the 3rd row by -8/41

Add -1/8 times the 3rd row to the 2nd row
Add -1 times the 3rd row to the 1st row

Add -3 times the 2nd row to the 1st row

2 by 7 + – is equals to 1 so we can say that x.
x=1-2/7
x=7/7-2/7
x=5/7