Qudratic functions

[gleaming swan]

1. Wait patiently for a helper to come along.
2. Once someone helps you, say thank you and close the thread with: ```diff
   +close

[still vessel]

total area is
(7+2x)(5+2x) and we want this to equal 80:
(7+2x)(5+2x)=80
4x²+24x+35=80
4x²+24x=45

for the factors you want to look for 2 numbers that multiply to -36 amd sum to -5
because a double negative is positive, we know that one has t be positive and one has to be negative:
4,-9 fits this
(x+4)(x-9) is the factorisation
and to check you can expand:
x²-9x+4x-36=x²-5x-36

[neon geyser]

thank you ! there's 17 more quetions if you're willing to help? i tried the quiz once already and didn't do too well :(

[still vessel]

wait this is an exam?

yeah I can't help with that any more

[neon geyser]

okay!

+close