Question 172691
f(x)= ax^2 + bx + c
f(0)= 5 
f(0)=a*0^2+b*0+c=5
f(0)=0+0+c=5
f(0)c=5 ans.
f(1)=10 
f(1)=a*1^2+b*1+5
f(1)a+b+5=10 multiply this equation by -2 & add.
f(2)= 19
f(2)=a*2^2+b*2+5
f(2)4a+2b+5=19 
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-2a-2b-10=-20
4a+2b+5=19 add.
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2a-5=-1
2a=-1+5
2a=4
a=4/2
a=2 ans.
2+b+5=10
b=10-5-2
b=3 ans.
Proof:
4*2+2*3+5=19
8+6+5=19
19=19