The equation would just be x=8 since the x of both points is 8.
4 x 5 - 3
= 20-3
=17<answer
F(x)=2x+3. easy as that, just replace y with f(x)
836 to the nearest hundred is 800 because number under 50 of the last two digits we round it below. Same thing as above 50 we round it up.
No srry but you can try asking someone else