Help please, solve and explain

Answer:
Step-by-step explanation:
17.
18.
f(x)=6x^2+7x-4
(a)
f(3)=6(3)^2+7(3)-4
=54+21-4
=71
(b)
f(m)=6m^2+7m-4
(c)
f(x+1)=6(x+1)²+7(x+1)-4
=6(x²+2x+1)+7x+7-4
=12x²+12x+6+7x+7-4
=12x²+19x+9
19.
(fg)(x)=f(g(x)=f(2x²+3)=2x²+3+5=2x²+8
20.
(a)
f(x)=x²+3x+4
domain:all real values
(b)
domain:all real values≥-2
(c)f(x)=log(x+7)
Domain:x≥-7
21.
x²+6x+y²-7=0
(x²+6x+6/2)²)-(6/2)²+y²=7
(x+3)²+y²=7+9
(x+3)²+y²=4²
center=(-3,0)
radius=4
22.
(x-3)²+(y-5)²=3²
or
x²-6x+9+y²-10y+25=9
x²+y²-6x-10y+25=0
Graph is for 17th question.