Question

4 raised to power two minus 8u minus 9=0​

Answer 1

Answer: u = $\frac{7}{8}$ or 0.875

Step-by-step explanation:

Let us convert this statement to a question

$4^{2}$-8u-9 = 0

16-8u-9 = 0

-8u = 0+9-16

-8u = -7

u = -7 ÷ -8

u = $\frac{7}{8}$ or 0.875

Answer 2

Answer:

x can be 3, -3, i, or -i.

Step-by-step explanation:

If you can't find the factoring by looking at this, simplify the equation.

let  

x

2

=

y

to make things easier to see

Now we have  

y

2

−

8

y

−

9

=

0

See it now?

We can factor into  

(

y

−

9

)

(

y

+

1

)

Now substitute back in  

x

2

for  

y

.

(

x

2

−

9

)

(

x

2

+

1

)

Since  

(

x

2

−

9

)

is a difference of two squares,

(

x

−

3

)

(

x

+

3

)

Now we have  

(

x

−

3

)

(

x

+

3

)

(

x

2

+

1

)

x can be 3, -3 for the first two parts

x

2

+

1

=

0

can become  

x

2

=

−

1

Taking the positive and negative root means  

x

=

±

√

−

1

Thus  

x

=

±

i

in addition to 3 and -3.