$x^{2} -8x=9 \\ x^{2} -8x+(-4)^{2} = 9 + (-4)^{2} \\ x^{2} -8x+16 = 9 + 16 \\ (x-4)^{2} =25 \\ x-4= \sqrt{25} \\ x-4= \pm 5 \\ x= \pm 5+4$
x = 5 + 4 or -5 + 4
x = 9 or -1

3 0

3 years ago

A 20 meter ladder rests vertically against the side of a barn. A pig that has been hitched to the ladder starts to pull the base

kirill115 [55]

Answer:

I hope my drawing explains well lol... h = 16

Step-by-step explanation:

So basically first you need to find x (the one in the drawing), by doing so, you just have to use the formula,

$speed = \frac{distance}{time}$

You substitute in the speed and the time given,

$0.4 = \frac{x}{30} \\ x = 12$

Then, you use the Pythagorean theorem,

$h = \sqrt{ {20}^{2} - {12}^{2} } \\ h = 16$

7 0

3 years ago

What is square root of 145 to 3 sf

steposvetlana [31]

The square root is 21025 and to 3 sf would be 21000?

3 0

3 years ago