Choose the correct simplification of the expression (3x − 6)(2x^2 − 4x − 5). 6x^3 − 24x^2 + 9x − 30 6x^3 + 9x + 30 6x^3 − 24x^2 + 9x + 30 6x^3 − 24x^2 + 39x + 30
Completely confused
\((3x − 6)(2x^2 − 4x − 5)\) So here you want to distribute
|dw:1539478681201:dw|
Okay okay hold on imma write it down
Okay
Okay done
\[(\color{red}{3x}\color{blue}{-6})(2x^2-4x-5)=\] \[(\color{red}{3x}\times 2x^2)+(\color{red}{3x}\times-4x)+(\color{red}{3x}\times-5)+(\color{blue}{-6}\times2x^2)+(\color{blue}{-6}\times-4x)+(\color{blue}{-6}\times-5) \]
Latex cut off RIP
\[(\color{red}{3x}\color{blue}{-6})(2x^2-4x-5)=\] \[(\color{red}{3x}\times 2x^2)+(\color{red}{3x}\times-4x)+(\color{red}{3x}\times-5)+\\(\color{blue}{-6}\times2x^2)+(\color{blue}{-6}\times-4x)+(\color{blue}{-6}\times-5) \]
Got it just writing it down :)
Okie done
Well just simplify those
Do you know how to do that?
Multiply the ones in () and then add?
Oh wait idk shoot o.o
Yes multiply the ones in parenthesis
What about the ones that are like 3x * -5
Multiply the number only, so it would be -15x
So is this right? \[6x^{2} + 12x + 15 - 12x ^{2} + 24x + 30\]
When multiplying exponents you add the exponent ex. \(x\times x^2=x^3\)
so 6x^2 would become 6x^3?
Right
Alright lemme fix
Okay done
Okay, what do you have?
\[6x^3 - 12x + 15x - 12x^3 + 24x + 30\]
Almost \((\color{red}{3x}\times 2x^2)=6x^3 ~~\\ +(\color{red}{3x}\times-4x)=-12x^2\\ +(\color{red}{3x}\times-5)=-15x\\ +(\color{blue}{-6}\times2x^2)=-12x^3\\+ (\color{blue}{-6}\times-4x)=24x\\ +(\color{blue}{-6}\times-5)=30\)
ohh
The power adding applies to all exponents \(x\times x=x^2\) \(x\times x^3=x^4\) \(number~\times x=numberx\)
time to rewrite
Alright i think i got it now
Okay
Idk what to do now ;-;
Add the numbers that have the same power of x ex. \(2x+5+3x+9\) = \(5x+14\) This applies to app powers!
So like 6x³ - 12x^3 ?
would the exponets add?
Yes, add the co-efficients
No exponents stay the same
So like this? 6x^3 + 12x^3 = 18x^3
Right
Okay so this is what i got. \[18x^3 - 12x^2 - 39x + 30\]
Ah! i goofed previously! \(\color{#0cbb34}{\text{Originally Posted by}}\) @dude Almost \((\color{red}{3x}\times 2x^2)=6x^3 ~~\\ +(\color{red}{3x}\times-4x)=-12x^2\\ +(\color{red}{3x}\times-5)=-15x\\ +(\color{blue}{-6}\times2x^2)=-12x^3\\+ (\color{blue}{-6}\times-4x)=24x\\ +(\color{blue}{-6}\times-5)=30\) \(\color{#0cbb34}{\text{End of Quote}}\) \(+(\color{blue}{-6}\times2x^2)=-12x^3\) Correction: \(+(\color{blue}{-6}\times2x^2)=-12x^2\)
Now i am confused...............
I made a mistake, in \(+(\color{blue}{-6}\times2x^2)=-12x^3\) I told you about the exponents rule right? I accidentally added an exponent here -6 doesn't have an x, so the \(x^2\) stays the same
This was just a mistake from my end
so it would be 18x^2?
\(6x^3\color{red}{-12x^2}-15x-12x^3+24x+30\) is your equation only the red segment is the change
Alright i fixed it
So now i do the same that i just did with adding them?
Yes
so 6x^3 + -12x^3?
\(-12x^3\) is \(-12x^2\) when I corrected myself So \(6x^3\) stays like that \(6x^3-12x^2-15x-12x^2+24x+30\)
Oh yeah dang it my bad
\[6x^3 - 12x^2 - 12x^2 - 15x + 24x + 30\] so like this^^^^
Right
both of the 12x^2 would cancel out?
They are both negative, they would add up
so it would end up being 24x^2?
-24x^2, yes, keep the sign
Okay
\[6x^3 - 24x^2 - 9x +30\] Like this?
Close, when adding −15x+24x You want to keep the sign of the greater number
so positive
Right
I got it now
So the answer would be C?
Yep
THANK YOUUUUUUUU
Iḿma end up writing it all back out and neater so i can get it again :D. Thanks again!
Okay, sure!
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