Question 52694: 1) x^2-13x+30=0
2) x^-0.7x-0.44=0
I never really understood how to solve qudratic equations which are equal to zero. Answer by funmath(2933) (Show Source):
You can put this solution on YOUR website! These can be solved by factoring:
is in the form
You need two numbers that multiply to give you c, in this case, +30.
But when you add them together you get b, in this case, -13.
-3*-10=+30
-3+-10=-13
(x-3)(x-10)=0
Use the zero product property and set each parenthesis equal to zero.
x-3=0
x-3+3=0+3
x=3
x-10=0
x-10+10=0+10
x=10
so x=3 and x=10
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For the next one it's not as obvious:
Two numbers that multiply together to get -.44
but add together to get -0.7
-1.1*0.4=-.44
-1.1+0.4=-0.7
(x-1.1)(x+0.4)=0
x-1.1=0
x-1.1+1.1=0+1.1
x=1.1
x+0.4=0
x+0.4-0.4=0-0.4
x=-0.4
x=1.1 and x=-0.4
For this one you could use the quadratic formula if you couldn't figure it out because of the decimals. The quadratic formula works every time, it's just not always the easiest method to use. If you want to see that one using the quadratic formula, resubmit it and say you want to see it solved using the quadratic formula.
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