Question

Find the zeros for 2x^2

- 24 = 26. What is the positive value of x?

Answer 1

The zeroes are -1 and 13

Positive value:
`x = 13`

Explanation:

Given

`2x^2 - 24x = 26`

Solving (a): The zeros

`2x^2 - 24x = 26`

Subtract 26 from both sides

`2x^2 - 24x - 26= 26-26`

`2x^2 - 24x - 26= 0`

Divide through by 2

`(1)/(2)(2x^2 - 24x - 26) = (1)/(2) * 0`

`x^2 - 12x - 13 = 0`

Expand

`x^2 - 13x + x - 13 = 0`

Factorize:

`x(x-13)+1(x-13)=0`

`(x+1)(x-13)=0`

Split:

`x +1 =0\ or\ x-13=0`

`x =-1\ or\ x=13`

Hence, the zeroes are -1 and 13

Solving (b): The positive value of x

In (a) above:

`x =-1\ or\ x=13`

The positive value is:

`x = 13`