Question 959048
{{{y=ax^2+bx+c}}}
So,
1.{{{27=4a+2b+c}}}
2.{{{61=16a+4b+c}}}
3.{{{142=49a+7b+c}}}
Subtract 1 from 2 and 1 from 3,
{{{16a+4b+c-4a+2b+c=61-27}}}
{{{12a+2b=34}}}
4.{{{6a+b=17}}}
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{{{49a+7b+c-4a-2b-c=142-27}}}
{{{45a+5b=115}}}
5.{{{9a+b=23}}}
Subtract 4 from 5.
{{{9a+b-6a-b=23-17}}}
{{{3a=6}}}
{{{a=2}}}
Then from 4,
{{{12+b=17}}}
{{{b=5}}}
and finally from 1,
{{{8+10+c=27}}}
{{{c=9}}}
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{{{y=2x^2+5x+9}}}