Answer:
-9 or negative 9
Step-by-step explanation:
The opposite of negative 9 is positive 9.
The opposite of <em>that</em> is negative 9.
5.7y-5.2=y/2.5
Add 5.2 to both sides:
5.7y = y/2.5 + 5.2
y/2.5 = 0.4y
5.7y = 0.4y + 5.2
Subtract 0.4y from both sides:
5.3y = 5.2
Divide both sides by 5.3:
y = 5.2/5.3
y = 0.98113
Answer:
8
Step-by-step explanation:
Let's just call the number x for simplicity.
So, 7x is 8 less than x².
Putting this into an equation would look like this
x² - 8 = 7x
It looks like we'll have to factor this to solve. Before we do that we need to move the 7x to the left side so that everything is together.
x² - 7x -8 = 0
Now, we can proceed. To factor we first need to find the factors of -8.
The factors of -8 are
-2 ⋅ 4, -4 ⋅ 2, -1 ⋅ 8, 1 ⋅ -8.
We need to find the pair of factors that adds up to -7. The only ones that do are -1 and 8.
So now that we have these we can create a pair of binomials using them. This will give us the factored form of this equation.
( x + 1 ) ( x - 8 )
To find the solutions we will have to set them to 0 and solve each of these binomials individually.
x - 1 = 0
x = 1
So, one of the solutions is 1. It's not the one we want, since it's positive.
x - 8 = 0
x = 8
This is the one we want since it is positive.
Answer:
Step-by-step explanation:
First you want to understand that every time a radio wave goes 300,000,000 meters a second passes, literally what meter per second means. of course it doesn't go that far, it goes 384,000 one way and then the same distance back, which makes 768,000. Under a third of the distance to make 1 second, so it will be less than one second.
You also want to understand the formula for speed. speed = distance / time. Whch also means, to find time you can change it to be time = distance / speed. And hey, we have distance and speed. 768,000 / 300,000,000 = .00256, I'll leave the significant figures to you unless you need help with them. but that's .00256 of a second. or .00256 s
