For f(x) = -4x + 5 , find f(2)
I feel so stupid but these are hard because no one explained them for me. here are the multiple choice answers...
a. 6
b. -3
c. 13
d. -13
2007-10-12 05:53:29 · 8 answers · asked by mathdummythatneedshelp 1 in Science & Mathematics ➔ Mathematics
When the equation says find f(2) means plug in the number 2 anywhere there is an "X". so it goes like this:
f(x) = -4x + 5, find f(2)
-4(2) + 5 = -8 + 5 = -3
f(x) means the function of x or in other words:
f(x) = y when graphing.
Hope this all helps!
2007-10-12 06:01:24 · answer #1 · answered by skibm80 6 · 0⤊ 0⤋
I'll explain it for you...
Given the equation f(x) = -4x +5
They want you to find f(2)
What it is asking in english terms is: what does the equation equal when x = 2. To find out, just subtitute 2 in for x in the equation.
f(x) = -4(2) + 5
f(x) = -8 + 5
f(x) = -3
Can also be written as f(2) = -4(2) + 5
f(2) = -8 + 5
f(2) = -3
f(x) = -3 when x = 2.....Both ways are the same and will get you the same answer. This second example just proves how the english terms make sense to remember what to do. In the problem they gave you an equation with an "x" variable in it and they gave you an f(x) value, 2. So they are saying x = 2, but you have to find "y" so f(x)= is actually y=
f(x)=-4x+5
y=-4x+5
So f(x) is just another way of saying y
2007-10-12 06:18:12 · answer #2 · answered by regisivjosh7 3 · 0⤊ 0⤋
y=-2x+1 and you can graph that by putting 1 on the y axis because it is the y-intercept and from the point (0,1) go down 2 and over to the right 1 (rise over run)...thats the graph and for the table put it as x y=-2x+1 y 2 y=-2(2)+1 -3 1 y=-2(1)+1 -1 0 y=-2(0)+1 1 -1 y=-2(-1)+1 3 -2 y=-2(-2)+1 5
2016-04-08 05:21:53 · answer #3 · answered by Anonymous · 0⤊ 0⤋
f(2) is nothing but substituting x value =2 in the given equation
so when u substitute
-4(2)+5
-8+5
-3
so the answer is b
2007-10-12 05:58:13 · answer #4 · answered by Siva 5 · 0⤊ 0⤋
All you do is substitute 2 for x.
f(x) = -4x + 5
f(2) = -4*2 +5
f(2) = -3
You may have learned this using y, instead of f(x), in Algebra I. It's the same concept.
2007-10-12 05:58:34 · answer #5 · answered by Steve A 7 · 0⤊ 0⤋
see its really simple just find f(2) tat means just place 2 in place of x in f(x)
ull get -4(2)+5=-8+5=-3
so choice b is correct
2007-10-12 06:08:51 · answer #6 · answered by rajini 2 · 0⤊ 0⤋
= - 4(2) + 5
= - 8 + 5
= - 3
Answer: b. - 3
2007-10-12 06:20:05 · answer #7 · answered by Jun Agruda 7 · 2⤊ 0⤋
b.
2007-10-12 05:56:33 · answer #8 · answered by chemistrychicka 1 · 0⤊ 0⤋