Hw do u factorise this ..its in decimals?? x^2+1.6-4.2=0 ??
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You didn't answer my question:)
should it be 1.6x ?
I'll assume it should
How about times both sides by 10 and see if that helps.
I think I will divide everthing by 2
I am looking for 2 numbers that multiply to -5*21 that is -105 and add to 8
Since the multply to a negative, one is neg and the other is pos.
Since they add to a positive, the bigger one will be the positive one.
some of The factors of 105 are 5,7,3, and 15-7=8
So the numbers are +15 and -7
Now i am going to replace 8x with 15x-7x
Now factorise in pairs
So either 5x-7=0 or x+3=0
so 5x =7 or x=-3
so x=7/5 or x=-3
do you know how to finish it?
It would have been easier just to use the quadratic formula with the original equation LOL :)
I thought you were suppose to do it by factorising - that is why I did it this 'hard' way.