#Can someone help me understand what to do here
19 messages · Page 1 of 1 (latest)
For both
My teacher ended up just anwsering the first few questions when trying to explain it to me
d) 8x^2 - 42x + 27
Step 1: Multiply 8 by 27:
8*27 = 216
Step 2: Find a multiple of 216 that’ll give you the sum of - 42:
1 216
2 108
3 72
4 54
6 36 <—
Step 3: Rewrite the multiple so it still multiplies to 216 but the sum equates too - 42:
-6 -36
Step 4: Rewrite the equation:
8x^2 - 6x - 36x + 27
Step 5: Drop the middle sign and factor out both parts:
2x(4x -3) - 9(4x - 3)
Step 5: Change into factor forms
(2X - 9) (4x - 3)
⬆️
Reply if you got any questions about a step
What do you mean drop the middle sign?
Step 4: Rewrite the equation:
8x^2 - 6x “-” 36x + 27
Step 5: Drop the middle sign and factor out both parts:
2x(4x -3) “-” 9(4x - 3)
Idrk how to explain it, just knows it’ll be between the two numbers that are the multiple of 216
Ok so just like separate the question in half
Yeah, basically!
How did you go from
2x(4x -3) -9(x -3)
To
(2x -9) (4x -3)
If you could just explain it in more detail
Also thanks for the help
No problem! As for the previous question, I cannot really explain it in any other way except that the two equate each other.
I mean the only other way is to just say
(4x -3) is similar in both, so you combine the two and what are you left with? 2x-9
I don’t really get what you mean by they are similar in both
Hey @slender sun is the anwser for question e)
(-4n + 21) (n + 1)
E) -4n^2 - 17n+ 15
Step 1: Multiply -4 by 15:
-4 * 15 = -60
Step 2: Find a multiple of -60 that’ll give you the sum of 17:
-3 20 <—
Step 3: Rewrite the equation:
-4n^2 -3n “+” 20n + 15
Step 4: Drop the middle sign and factor out both parts:
-N(4n + 3) + 5(4n +3)
Step 5: Change into factor forms
(-N+5)(4n+3)
I got this