Question

heellpppp.....
solve using substitution u=x+3
2(x+3)^2-17(x+3)=-21

Answer 1

\[2u^2-17u+21=0\] is a start

Answer 2

by some miracle this one factors as
\[(2u-3)(u-7)=0\] and so you can solve for \(u\) easily, then replace \(u\) by \(x+3\) and solve for \(x\)

Answer 3

ok so before i plug in back the x+3 i got u=7 and for my other solution it is negative 3/2? right?

Answer 4

never mind its positive

Answer 5

its positive but then you need to use 3/2-3. Then solve. Remember to use the same denom.

Answer 6

You should get the right answer. Then plug it back in to see if you equation is right.

Answer 7

Could you explain how did you get the factors satellite73?