Each pencil costs 0.72 as you do 4.32 / 6
Answer:
k=2
Problem:
if the equation x^2 +(k+2)x+2k=0 has equal roots,then the value of k is ..
Step-by-step explanation:
Since the coefficient of x^2 is 1, we can use this identity to aid us: x^2+bx+(b/2)^2=(x+b/2)^2.
So we want the following:
[(k+2)/2]^2=2k
Apply the power on the left:
(k+2)^2/4=2k
Multiply both sides by 4:
(k+2)^2=8k
Expand left side:
k^2+4k+4=8k *I used identity (x+c)^2=x^2+2xc+c^2
Subtract 8k on both sides:
k^2-4k+4=0
Factor using the identity mentioned a couple lines above:
(k-2)^2=0
Since zero squared is zero, we want k-2=0.
Adding both sides by 2 gives k=2.
5854 out of 10000 because it is 5854 ten thousandths
Answer:
25 math problems
Step-by-step explanation:
He completed 10 out of x, or the total he has to do.
10/x
We know that this equals 40%
10/x=40/100
Cross multiply to solve
40*x=100*10
40x=1000
Divide both sides by 40
x=25
He must do 25 math problems
