I think it’s b hope it helps
5x^2-4x+1 + -3x^2+x-3= 2x^2-3x-2
Mean is a form of average, and in order to find this we add up all the numbers then divide by the amount of numbers we have.
So, we have 5 numbers here. (8, 17, 9, 3, and 13)
8 + 17 + 9 + 3 + 13 = 50
50/5 = 10
The mean of those five numbers is 10.
Let the 1st number be x; 2nd number be y; 3rd number be z.
x + y + z = 79
x = number we are looking for.
y = x * 5 ==> 5 times the first
z = x + 16 ==> 16 more than the first
Therefor,
x + (x * 5) + (x+16) = 79
1st step, multiply the 2nd number: x * 5 = 5x
x + 5x + x + 16 = 79
Add all like numbers:
7x + 16 = 79
To get x, transfer 16 to the other side and change its sign from positive to negative.
7x = 79 - 16
7x = 63
To get x, divide both sides by 7
7x/7 = 63/7
x = 9
To check. Substitute x by 9.
x + (x * 5) + (x+16) = 79
9 + (9 * 5) + (9 + 16) = 79
9 + 45 + 25 = 79
79 = 79 equal. value of x is correct.
It should be 270 since 6 x 9 x 10 x 1/2= 270
