Question

Simplify.
2x − 2y + 5z − 2x − y + 3z

Answer 1

Choices are
a. x − 3y + 8z
b. 2x − 2y + 8z
c. 3y + 8z
d. −3y + 8z

Answer 2

@Michele_Laino

Answer 3

look at just the terms with "x" in them
2x -2x

what is 2x take away 2x ?

Answer 4

0

Answer 5

yes. in other words, the answer will *not* have an "x" in it
so you can cross off those choices that have an x

Answer 6

to get the full answer, now look at the y's
-2y - y

how many negative y's do we have ?

Answer 7

3 technically speaking
c. 3y + 8z
d. −3y + 8z

Answer 8

-2y-y is -3y

so the answer has a -3y in it

Answer 9

okay so
c. 3y + 8z
d. −3y + 8z
its d right and please stay i need more help

Answer 10

im in middle school taking algebra honours

Answer 11

Shelly and Terrence completed a different number of tasks in a game. Shelly earned 90 points on each task. Terrence's total points were 20 less than Shelly's total. The expression below shows Terrence's total points in the game:

90x − 20

What does the factor x of the first term of the expression represent?

A. The total number of tasks Terrence completed
B. The total number of tasks Shelly completed
C. The sum of Shelly's and Terrence's total points
D. The difference between Shelly's and Terrence's total points

Answer 12

focus on
90 points on each task

if you did 1 task, you get 90
2 tasks you get 2*90 (= 180)
3 tasks you get 3*90
etc

Answer 13

hint:
\(90x\) is the total of Shelly

Answer 14

what about the 20

Answer 15

they did not ask about the 20
but they tell you
Terrence's total points were 20 less than Shelly's total

so you figure out Shelley's points and subtract 20 to get Terrence's

Answer 16

so x is how many tasks shelly completed

Answer 17

The question is "what does the 'x' represent?"

yes, x is the (unknown) number of tasks shelly did

Answer 18

thanks i may need more help so stay please

Answer 19

and the way we know that is we expect to see
90* number of tasks (because we are told 90 points on each task and we know we should multiply the 90 times the number of tasks to get the total)
we then match up what we expect
90 * number of tasks
with the
90x part of 90x-20
to decide x is the number of tasks

Answer 20

Evaluate the following expression using the values given:

Find 2r^2 + 3s^3 − r^2 + 4t^2 − r^2. if r = −2, s = −3, and t = 5.

A.−19
B.−37
C.27
D.19

Answer 21

oh thanks

Answer 22

replace the letters with their number and simplify
the only trick part is if you have a negative number, so use parens
for example r^2 becomes
\[ (-2)^2 \]
and that means -2*-2 which is 4

Answer 23

okay

2(2)^2 + 3(-3)^3 − 2^2 + 4(5)^2 − (2)^2

Answer 24

yes, but I thought r was -2 not +2

Answer 25

-2^2=4 tho

Answer 26

also, doing that way gets the correct answer, but notice (looking only at the r^2 terms) you have
2r^2 - r^2 -r^2
and that simplifies to 0
so we could ignore doing those terms

if you have a - b^2 that means a - b*b
in your problem - r^2 means - (-2)*(-2) = - 4

Answer 27

-4 is not a choice

Answer 28

-2^2=4

Answer 29

You are doing
Find 2r^2 + 3s^3 − r^2 + 4t^2 − r^2. if r = −2, s = −3, and t = 5.

the fastest way to do this is notice
2r^2 - r^2 - r^2 is what ?

Answer 30

2^-2

Answer 31

you have 2 r^2 and take away an r^2
then take away another r^2

Answer 32

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Answer 33

0

Answer 34

yes, that means after you simplify the r^2 stuff you are left with
3s^3 +4t^2

with s= -3 and t=5

replace s with (-3) and t with (5) to get
\[ 3 (-3)^3 + 4(5)^2 \]
now simplify, remember order of operations, exponents before multiply

Answer 35

-81+100=19

Answer 36

yes

Answer 37

if you keep the original equation
2r^2 + 3s^3 − r^2 + 4t^2 − r^2. if r = −2, s = −3, and t = 5
you should get the same answer (but with more work)

Answer 38

okay

2x^2 − 2z^4 + y^2 − x^2 + z^4 if x = −4, y = 3, and z = 2

Answer 39

First, can you simplify a little ?

Answer 40

yes
32-32+9-16+16

Answer 41

=9??????????

Answer 42

yes, but you could have first simplified by noticing you have
2x^2 - x^2 and that is x^2
also -2z^4 +z^4 is -z^4

so the problem simplifies to
x^2 + y^2 -z^4

Answer 43

then you put in -4 for x , 3 for y and 2 for z to get
16+9-16
and that becomes 9

Answer 44

yay almost done

Answer 45

you should make a new post.