Answer:
225/4
Step-by-step explanation:
When you are trying to find the number to be added to a binomial of the form :
in order to make it a perfect square trinomial, all you need to do is to use the square of half of the coefficient b. That is :
.
In your case this is:
Here is the equation: x+(x+20) = 120
Since you can't combine anything yet, its x+x+20=120
You need to get x by itself
Minus 20 from both sides
Its x+x=100 now
Combine the x's which is now 2x
Now divide 100 by 2 which is 50
x=50
---------------
Lets check:
50+(50+20)=120
Now combine the numbers in the parentheses
Its now 50+70=120
50+70=120 and 70-50=20
As you can see, he ran 50 minutes the first day and 70 minutes the second day
The probability that a student will fail is 3/25, there are 25 of them, thus the sample space is 25 and 3 out of that is 3/25 or 0.12.
what's the probability that one will pass? well, the opposite of failing, thus is the complement of 0.12, namely, 1 - 0.12.
For this case we must find the value of "x" that meets the following equation:

We subtract
on both sides of the equation:

We simplify:

Finally, 
Answer:

Answer:
x = 8 or x = -2
Step-by-step explanation:
x^2 - 6x + 9 = 25
x^2 - 6x - 16 = 0
The formula to solve a quadratic equation of the form ax^2 + bx + c = 0 is equal to x = [-b +/-√(b^2 - 4ac)]/2a
with a = 1
b = -6
c = -16
substitute in the formula
x = [-(-6) +/- √(-6^2 - 4(1)(-16))]/2(1)
x = [6 +/- √(36 + 64)]/2
x = [6 +/- √10]/2
x = [6 +/- 10]/2
x1 = [6 + 10]/2 = 16/2 = 8
x2 = [6 - 10]/2 = -4/2 = -2