what are/is the roots of "3x(square) - 25x + 40"?

Question

3x square ok! dont know how to make a square sign or a little 2

Answer 1

You only can say
Root[x^2 - 25x + 40]
Type for x sq only x^2.

Th

Answer 2

The roots are
x = (25/6)+(1/6)*(145^(1/2)) and X= (25/6)-(1/6)*(145^(1/2))

This is because for equation ax^2 + bx + c= 0
The roots are x = [-b (+or-) sqrt(b^2 - 4ac)] / 2a

Comparing with 3x^2 - 25x + 40=0, we get
a = 3, b=-25, c=40

So, x = [-(-25) (+or-) sqrt((-25)^2 - 4*3*40)] / 2*3
=> x = [25 (+or-) sqrt(625 - 480)] / 6
=> x = [25 (+or-) sqrt(145)] / 6
=> x = (25/6) (+or-) [sqrt(145)] / 6

I hope, I answered your question.

All the best.

Answer 3

3x^2 - 25x + 40
use the quadratic formula
x1 = [-(-25) + sqrt((-25)^2 -4*3*40)]/(2*3)
x1 = [25+sqrt(625 - 480)]/6
x1 = [25+sqrt(145)]/6
x1 = 6.17

x2 = [-(-25) - sqrt((-25)^2 -4*3*40)]/(2*3)
x2 = [25-sqrt(625 - 480)]/6
x2 = [25-sqrt(145)]/6
x2 = 2.16

Answer 4

you need to use the quadratic formula or your graphing calculator.

the answers become (6.1736,0) and (2.15873, 0)

To get anwer using calculator you need to first graph the function. Then depending on the brand of the calculator you need to find the zero's of the graph (where it crosses the x-axis)

To get answer algebracially use the quadratic formula. This website explains it and shows you the formula.

http://www.purplemath.com/modules/quadform.htm

Answer 5

6.173599, 2.15973