```Question 327999
4/5 and 4/7 are opposites? How?
Either graph the equation or use the discriminant to determine the number of real roots.
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{{{y^2-(4/5)y-4/7=0}}}
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{{{graph(300,300,-5,5,-10,10,x^2-(4/5)x-4/7)}}}
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The function crosses the x axis twice, two real roots.
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{{{x^2+6x+9=25 }}}
{{{x^2+6x-16=0}}}
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{{{graph(300,300,-10,10,-15,5,x^2+6x-16)}}}
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How many roots? What are they?
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{{{9x^2+12x+4=0}}}
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{{{graph(300,300,-3,3,-1,5,9x^2+12x+4)}}}
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x-intercept: Where does the function cross the x-axis?
y-intercept: Where does the function cross the y-axis? Value for f(x) when x=0.
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You can't factor x out but you can factor two of the equations.
For the first equation, you need to either complete the square or use the quadratic formula.
Equation 2:
{{{x^2+6x-16=0}}}
{{{(x-2)(x+8)=0}}}
Two solutions:
{{{x=2}}} and {{{x=-8}}} are the x-intercepts.
{{{y=0^2+6(0)-16=-16}}} is the y-intercept.
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Equation 3:
{{{y=9x^2+12x+4=0}}}
{{{(3x+2)(3x+2)=0}}} <--- Double root
{{{3x+2=0}}}
{{{x=-2/3}}} is the x-intercept
{{{y=9(0)^2+12(0)+4=4}}} is the y-intercept
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