This would be a combination I believe not a permutation so the equation to use would be nCr= n!/(n-r)!r!
So 10C2=45
For # 3 and 5 you need to use the quadratic formula:
<span>(-b +/- srt(b^2 - 4ac))/2a </span>
<span>a, b, and c are representative of this formula: ax^2 +bx + c </span>
<span>1) 2x^2+3x-9=0 </span>
<span>(2x - 3)(x + 3) = 0 </span>
<span>2x - 3 = 0, x + 3 = 0 </span>
<span>+3 +3, -3 -3 </span>
<span>2x = 3, ***x = -3*** </span>
<span>/2 /2 </span>
<span>***x = 3/2*** </span>
<span>2) 5x^2+2x=0 </span>
<span>(x)(5x + 2) = 0 </span>
<span>5x +2 = 0, ***x = 0*** </span>
<span>-2 -2 </span>
<span>5x = -2 </span>
<span>/5 /5 </span>
<span>***x = -2/5*** </span>
<span>4) 4x^2+7x-2=0 </span>
<span>(4x - 1)(x + 2) = 0 </span>
<span>4x - 1 = 0, x + 2 = 0 </span>
<span>+1 +1, -2 -2 </span>
<span>4x = 1, ***x = -2*** </span>
<span>/4 /4 </span>
<span>***x = 1/4***</span>
Answer: 20.25 m
Step-by-step explanation: To find the area of a triangle, use the formula (b•h)/2. Using this formula, substitute the numbers:
(9•4.5)/2
Then solve.
40.5/2
20.25
Answer:
x is equal to negative one, and y is equal to negative four.
Step-by-step explanation:
You can do this by solving one of the equations by either x or y, then substituting it into the other. Let's solve the second one for y:
Now we'll substitute that into the first equation:
So we now know that x is equal to -1. We can simply substitute that into one of the original equations to find y:
We now know that x is equal to -1, and y is equal to -4. We can also check our answer by plugging that -4 into the other equation, and see if we still get -1:
So we know that our answer is correct.
Answer:
The greatest growth was between 3 and 4 years. The growth between those years was about 32%
Step-by-step explanation:
