Answer:
Step-by-step explanation:
1 ) k²-8k = 0
k(k-8)=0
k = 0 or k=8
2) a²+5a=0
a(a+5) = 0
a=0 or a = - 5
3 ) 6n²+5n-25=0
delta = b²-4ac b =5 and a = 6 and c= - 25
delta = 5²-4(6)(-25) = 625 = 25²
n 1 = (-5+25)/12 = 20/12 = 5/3
n 2 = (-5-25)/12 = - 30/12 = -5/2
same method for 4) and 5)
Answer:
f^(-1)(x) = \frac{-1}{5} (x+4)
Step-by-step explanation:
Given is a function

To find its inverse.
We must check whether f is one to one or onto first
If -5x1-4 = -5x2-4 we get x1=x2
Hence f is one to one
Also for every f(x) we can find a x so f is onto.
So inverse exists
Let

Replace x by f inverse and y by x

Answer:
2
Step-by-step explanation:


4x + 8y = 40
4x + 8(0.8) = 40
4x + 6.4 = 40
40 - 6.4 = 33.6
33.6 / 4 = x
33.6 / 4 = 8.4
The answer option 2, 8.4
Answer:
cos − 1 ( x ) [ − 1 , 1 ] [ 0 , π ]