$30/ 3 sweatshirts = $10 /shirt
$ 10/shirt * 4 shirts = $40
It would cost $40
Answer:
Wouldn't it be 45 minutes as well?
Step-by-step explanation:
If you think about it in a real life scenario, if one person does the job and then another person does the same job at the same speed wouldn't it be the same time? But if its not i think it would be 15 minutes because 45-30 = 15
Answer:
roots : 4, -4, i, -i
Step-by-step explanation:
This gets a bit tricky.
We have to substitude x^2 as u in this problem.
Now to rewrite x^4 − 15x^2 − 16 = 0 with u, we get
u^2 - 15u - 16 = 0
( u - 16) (u + 1)
U = 16
U = -1
<em>This is not the end of the problem. </em>
Now we have to substitute x^2 back to u.
x^2 = 16 --> we get the roots 4 and -4
x^2 = -1 --> we get the roots i and -i
tadah!
