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June 17th, 2018, 02:50 AM   #1
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Question Please help me, as I'm really bad at math...

Let f(x)=3x-2x-1
g(x)=x²-1
h(x)=f(x)+g(x)

a. (f -g) (x)
b. f(-1) ⋅ g(2) ⋅ h(0)
c. g(x)/f(x)
d. h(x-1)
e. f(3)+g(2)

Please help me. I really don't understand any of these; I'm really really bad at math. It's not that I don't listen, because I do listen, but I just don't understand when my teacher explains, and it's not my teachers fault, I'm just really really fucking dumb, I just copied what my teacher wrote on the board. Please help me with steps too, thanks...

Last edited by skipjack; June 17th, 2018 at 09:21 AM.
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June 17th, 2018, 09:11 AM   #2
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What do you understand?
Can you solve something simpler, like:
5x + 12 = 3x + 20

Can you solve that for x ?
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June 17th, 2018, 09:36 AM   #3
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The equations
f(x) = 3x - 2x - 1
g(x) = x² - 1
h(x) = f(x) + g(x)
are to be treated as definitions of f(x) and g(x) in terms of x, and of h(x) in terms of f(x) and g(x). Note that "3x - 2x - 1", if that was typed correctly, can be simplified to x - 1.

Note that terms such as "3x" mean "3(x)" (the product of 3 and x), but "f(x)" doesn't mean the product of f and x.

To evaluate f(-1), one replaces each "x" in "f(x) = 3x - 2x - 1" with "-1".
Doing that gives f(-1) = 3(-1) - 2(-1) - 1. The right-hand side evaluates to -6.

The above should help with doing parts b and c of the question.
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June 17th, 2018, 10:45 AM   #4
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OP, is f(x)=3x-2x-1 supposed to be perhaps $f(x)=3x^2-2x-1$? Otherwise 3x - 2x = x.
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