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# I need help

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A parabola with equation  y=ax^2+bx+c contains the points (-3,3), (1,3), and (0,0). Find the value of 100a+10b+c.

Oct 27, 2020

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A parabola with equation y=ax^2+bx+c contains the points (-3,3), (1,3), and (0,0). Find the value of 100a+10b+c.

Hello Guest!

$$y=ax^2+bx+c$$         $$y=x^2+2x$$

$$3=9a-3b+c\\ 3=a+b+c\\ 0=0+0+c$$

$$c=0$$

$$9a-3b=a+b\\ 8a-4b=0\ |\ \cdot 3\\ \underline{9a-3b=3}\ |\ \cdot 4$$

$$24a-12b=0\\ \underline{36a-12b=12}\\ 12a=12$$

$$a=1$$

$$3=a+b+c\\ \underline{3=1+b+0}$$

$$b=2$$

$${\color{blue}100a+10b+c}=100\cdot 1+10\cdot 2+0\color{blue}=120$$

!

Oct 27, 2020