Mammoth Memory

Using the quadratic formula solver Example 4

Solve           `2x^2-7x+6=0`

`x=(-b+-sqrt(b^2-4ac))/(2a)`

Quick sketch

Therefore   `a=2` , `b=-7`  &  `c=6`

`x=(-(-7)+-sqrt((-7)^2-4times2times6))/(2times2)`

`x=(7+-sqrt(49-48))/4`

`x=(7+-sqrt1)/4`

`x=(7+-1)/4`

`x=(7+1)/4`   or  `x=(7-1)/4`

`x=8/4`   or  `x=6/4`

`x=2`   or  `x=1\1/2`

 

Now check your answer

`2x^2-7x+6=0`

 

If `x=2`                     `2times2^2-7times2+6=0`

`8-14+6=0`  Which is correct

If `x=1\1/2`                `2times(3/2)^2-7times(3/2)+6=0`

`2times(9/4)-21/2+6=0`

`18/4-21/2+6=0`

`4\2/4-10\1/2+6=0`

`4\1/2-10\1/2+6=0`  Which is correct

Answer:

The roots of `2x^2-7x+6=0`   are  `x=2`   or  `x=1\1/2`