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!
Answer:
10.95 (if you need to round 11)
Step-by-step explanation:
:p
Answer:
Step-by-step explanation:
let the number of dimes=x
and number of quarters=y
x=2y
0.10 x+0.25 y=2.25
or 10x+25y=225
divide by 5
2x+5y=45
2 ×2y+5y=45
4y+5y=45
9y=45
y=45/9=5
x=2y=2×5=10
Hence dimes=10
quarters=5
Answer:
13
Step-by-step explanation:
243.50 - 130.50 = 104
104 ÷ 8 = 13
