2 is the lie and 1 and 3 are truths
Step-by-step explanation:
#1 : if you looking for x intercepts make y=0
0=2x^2+4x
0=2(x^2+2x)
Divide both sides by 2
0=x^2+2x
0=x(x+2)
Therefore x=0 or x=-2
1 is true
#2
We can sub in the value to see if it is true
2(-14,70)^2-42(-14.70)=1049,58
Therefore 2 is a lie
#3
we can solve
To find x we make y=0
0=3(x-5)^2-12
0=3(x^2-10x+25)-12
0=3x^2-30x+75-12
0=3x^2-30x+63
0=3(x^2-10x+21)
Divide both sides by 3
x^2-10x+21=0
Factorise
(x-7)(x-3)=0
Therefore x=7 or x=3
Therefore 3 is a truth
