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Comment on Evaluate Expression with 37’s
If I let a=37, then a^2-23a-a
What answer are you getting
What answer are you getting when you evaluate the expression?
Hi if i let x=37, I get the
then, x^2 - 38x - x
then, x^2 - 39x
then, x(x-39)
which gives me 0 and 39 as possible values for x when I put the equation = 0
I chose 0 because its one of the answer choices. I know its wrong from the video but could you explain why.
The small error you just made
The small error you just made is very common.
Once you saw got to the EXPRESSION x(x-39), you transformed it into the EQUATION x(x-39) = 0.
However, there is no such EQUATION.
We still need to find the VALUE of x(x-39) when x = 37
So, we must take x(x-39) and replace the x's with 37's
We get: 37(37-39)
Simplify to get: 37(-2)
Evaluate to get: -74
Does that help?
Cheers,
Brent
It did! ;)
Could you factor out 37 after
I got the same answer, but is this just a coincidence? Or even if it's not a coincidence. Is there more room to make a mistake by factoring out 37 instead of the way you showed above. I hope that made sense. Thanks
Great idea!
Great idea!
We can definitely evaluate the expression by first factoring out of the 37.
We get:
37² - (23)(37) - 37 - (37)(15) = (37)(37) - (23)(37) - 37 - (37)(15)
= 37(37 - 23 - 1 - 15)
= 37(37 - 23 - 1 - 15)
= 37(-2)
= -74
Cheers, Brent
Very Clear