## fluffyunicorn Group Title how do i factor y=0.05x^2-x+1 2 years ago 2 years ago

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1. satellite73 Group Title

you cannot, at least you cannot using rational numbers

2. fluffyunicorn Group Title

how do you solve it with quadratic formula? i dont think my answer was right?

3. Monkeyball Group Title

$y=0.05x^2-x+1$ $\begin{array}{*{20}c} {x = \frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}} & {{\rm{when}}} & {ax^2 + bx + c = 0} \\ \end{array}$

4. Monkeyball Group Title

in this case a=0.05 b=-1 c=1

5. satellite73 Group Title

if it was me, i would multiply everything by 20 and write $x^2-20x+20=0$

6. satellite73 Group Title

makes life a lot easier to deal with whole numbers instead of decimals

7. Monkeyball Group Title

so I did it wrong?

8. fluffyunicorn Group Title

i know the formula but after i did it it looked wrong i got 1+-(sr).8/.1

9. satellite73 Group Title

no it is just easier if it is not clear where i got the 20 from, lets clear the decimal by multiplying everything by 100 you get $5x^2-100x+100=0$ then divide by 5 and get $x^2-20x+20=0$

10. satellite73 Group Title

you really do not want to take square roots of decimals or divide by decimals use whole numbers

11. fluffyunicorn Group Title

alright thank you!

12. satellite73 Group Title

for $x^2-20x+20=0$ it is probably easiest to complete the square because 20 is even i would write $x^2-20x+20=0$ $x^2-20x=-20$ $(x-10)^2=-20+100=80$ $x-10=\pm\sqrt{80}=4\sqrt{5}$ $x=10\pm4\sqrt{5}$

13. fluffyunicorn Group Title

And its not factorable right?