Question

f(x)=-2x+3 how do you find x if f(x) = 11

Answer 1

since we know f(x)=11 all we need to do is substitute and solve. so
11=-2x+3 subtract 3 from both sides
8=-2x divide both sides by -2
-4=x
sub back in to check

-2(-4)+3=8+3=11 looks good