8. The area of a rectangular painting is given by the trinomial x2 + 4x – 21. What are the possible dimensions of the painting? Use factoring. (1 point)

Do you know factoring of quadratic expressions?

no. i don't know any of this. honestly. aha.

Oopsie...

@Callisto can you continue?

?

you quit fast enough @ParthKohli :P

lgba has a tutorial btw

ok. so i'm assuming you don't know? lololololol.

I do know.. it's a long explanation. Do you want me to teach it to you?

Area = length times width. Since you're given the area, you need to factorise the expression given for the area. Am I on the right track @ParthKohli ?

Exactly :D

no. sorry. but when people explain me things over the computer i don't really understand. i'm not smart at all. aha, i'm just trying to pass this final cause i have a 62% and i can't fail the final or i fail the grade.

lgba....link your tutorial please

@ParthKohli I agree :|

hmm we can try...

i'm confused?

http://www.youtube.com/watch?v=nOZTe8jU2g4 Here you go

its not working?

lol just teach her parth :p

9. The area of a rectangular barnyard is given by the trinomial 12x2 + 14x – 40. What are the possible dimensions of the barnyard? Use factoring. (1 point) – 4x + 10 and –3x + 4 is that right?

close...but no

if you multiply that you'll get \[12x^2 - 16x - 30x + 40\]

4x – 10 and 3x + 4

A very very long explanation....I'll get tired.

....is this multiple choice?

yeeah.

lol clever ;D

is that the correct answer?

i encourage you to solve it though

and no it isnt....i shall shush now...

well i don't get it.. so i don't know.

Let me explain it in a nutshell. You must split the middle term so that in the expression \(ax^2 + bx + c\), we have the sum of the two split co-effecients as b. Also, the split co-efficients must have a product as the product of a and c.

this is a bad technique...but do trial and error on your multiple choice :p

Lol this is the only way to factor :P

<---does trial and error

..do you want to know how to do it? or just know the answer?

You can multiply in all the choices and see if the product is same as the trinomial.

Sorry.. I'm not in the mood of writing today :(

the answer.

Not allowed to give the answer.

ok.

do you know how to multiply binomials?

\(\Large \color{Black}{\Rightarrow x^2 + 4x + 21 = x^2 + 7x - 3x + 21 }\) Enough of hints.

(x+7)*(x-3) factor the equation and solutions are easily visable as 7 and 3

*facepalm* @timo86m

I am asking

whats your question @timo86m

would 7 and 3 be the answer it will be actually -7 and 3 but I think they are absolute values.

just message me @timo86m

Join our real-time social learning platform and learn together with your friends!