First, let us find the slope of 4x- y = -8.
-y=-4x-8
y=4x+8
It can be any equation with a slope that is the opposite reciprocal of 4 which is -1/4.
answer: y=-1/4x is a possible equation
I am going to explain this using the substitution method, considering it appears to be the best in this situation.
We know (from the bottom equation) that y can equal 3x+20. Using this knowledge, we substitute the y in the top equation for 3x+20. Now, we have an equation that looks like this:
3x+20=x^2+2x
Now we need to move x to one side and then do some radicals (square roots).
Subtract the 2x on the right (since it is smaller, negatives = NONONO), which will give you
x+20=x^2
Now, we take the square root of both sides to get
rad(x+20)=x
Now we have to simplify. 20 doesn't have a square root, but 4 goes into 20, and 4 has a square root of 2. This now becomes
2rad(x+5)
This doesn't simplify any further... we have a problem... no way to isolate x as far as my knowledge goes... Sorry, can't help you any further than that, but another person or your teacher might be able to. R.I.P...
I believe its sectors of a circle
Study this example to see if it helps.
<span>The scores on a certain math test were normally distributed with a mean score of 80 and a standard deviation of 5. What percent of the students scored between 80 and 90?</span>
If the mean (μ) is 80, and the standard deviation (σ) is 5, then all scores between 80 and 90 would fall between 0 and 2 standard deviations above the mean. Using the equation for Z score (Z = (X-μ)/σ) for each X value (80 and 90) then the Z scores are 0 and 2, respectively. Using a normal distribution table, it can be found that P(80 < z) = .5 (this is the probability that a random score would be greater than 80. It makes sense that it is .5 or 50% because 80 is the mean.)And the P(90 > z) = .97725. (this is the probability that a random score would be less than 90.) So the final answers would be (90 > z)-P(80<z) = .47725 or 47.725%