Question

Find -3a^2 - b^3 + 3c^2 - 2b^3 if a = 2, b = -1, and c = 3 ^=exponent
Please help I'm way beyond confused

Answer 1

The same method as u have done bfore.. just plug in the value of a,b and c. make a try.. i'll help if there are any issues....

Answer 2

ok
-3(2)^2-(-1)^3+3(3)^2-2(-1)^3=

Answer 3

Thats simplfyed soooo

Answer 4

-3x2= -6^2= -36
-1^3=-1
-36-(-1)= -37
3x3=9^2= 81
-37+81=44
-1= 43 :) is that correct

Answer 5

You have to be more careful
-3(2)^2-(-1)^3+3(3)^2-2(-1)^3=

-3(2)^2 means -3*2*2
can you simplify that ?

Answer 6

36positive or 12?

Answer 7

@midhun.madhu1987

Answer 8

do it in steps
-3*2*2

first do -3*2
what do you get ?

Answer 9

-6

Answer 10

now do -6 * 2
what do you get ?

Answer 11

-12?

Answer 12

yes
-3*2*2= -12
do you see how to do it ? could you do it yourself ?

Answer 13

can you still be here just in case i do something wrong

Answer 14

ok

Answer 15

can you try
-(-1)^3

first, it means - (-1)*(-1)*(-1)
-1*-1 is what ? (remember 2 minus makes a plus)

Answer 16

-3(2)^2-(-1)^3+3(3)^2-2(-1)^3
-12-3+81-1=

Answer 17

is that correct??

Answer 18

so far

Answer 19

we should do each term, one at a time, until you get expert.
-(-1)^3

first, it means - (-1)*(-1)*(-1)
-1*-1 is what ?

Answer 20

ohh -2 :)

Answer 21

and -2*-1= -3

Answer 22

-1 * -1 is negative time negative. remember: 2 minus make a plus

try again.

Answer 23

2 then not -2

Answer 24

when you MULTIPLY, and you see two minus signs, cross them off
change -1 * -1 to 1 * 1 (because we are multiplying, and when we see two minus signs, we can erase them... try to remember that rule)

Answer 25

when you see -1 * -1, make it 1*1
what is 1 times 1 ?

Answer 26

1

Answer 27

- (-1)*(-1)*(-1)

we do the -1 * -1 and it is 1
- ( 1* -1)

1*-1 is -1

-(-1)
what is that ?

Answer 28

huhhh :((( what am I subtracting it from

Answer 29

we are doing the 2nd term in
-3(2)^2 -(-1)^3 +3(3)^2-2(-1)^3

which is -(-1)^3

if that seems confusing, change the - to -1*
-1*(-1)^3

now write (-1)^3 as -1*-1*-1
and the problem is
-1*-1*-1*-1

if you write it this way
(-1 *-1) * (-1 * -1)

can you simplify that ?

Answer 30

hmmm...

Answer 31

i'm starting to think its just 1 but thats not what it is?

Answer 32

(-1 *-1) is 1 (remember the rule minus times minus, make it positive
1*1
and 1 times 1 is 1

that means
(-1 *-1) * (-1 * -1)
becomes
1 * 1

and 1 times 1 is 1

so the answer is
-(-1)^3 = 1

Answer 33

thats it is that the whole answer to the whole ? or just that part?

Answer 34

just the second term
so far we have
-12 + 1

now the 3rd term
3(3)^2

first, rewrite the (3)^2 using multiply. can you do that ?

Answer 35

9 righttt? and then overall its 81

Answer 36

3(3)^2

the (3)^2 means 3*3
3(3)^2 means 3* (3)^2 or 3*3*3
that is not 81

Answer 37

27 :) how do i not remember that

Answer 38

ok now we have
-12 + 1 + 27

now the last term
-2(-1)^3
remember this means
-2 * (-1)^3

and (-1)^3 means what ?

Answer 39

3?

Answer 40

exponents mean multiply by itself (*not* add)

Answer 41

ya -1*-1*-1=3 right because if there are negatives its a positive

Answer 42

you added. multiply is different.
and the rule is 2 negatives make a positive. that means you can erase *two* of the minus signs, but that leaves one still there.

so first, use the 2 minus make a plus to change
-1*-1*-1 to 1*1*-1
now multiply (not add)

Answer 43

0???

Answer 44

or -1

Answer 45

1*1 is ?

Answer 46

1

Answer 47

and 1*-1 is ?

Answer 48

-1*-1*-1 is (-1 * -1) * -1
and that is 1 * -1
and that is -1

Answer 49

so its -1 ok :) that makes since then

Answer 50

now we can do
-2 * (-1)^3
which is
-2 * -1

what is that ?

Answer 51

2 :)

Answer 52

so now you have
-12 + 1 + 27 + 2

Answer 53

18 :)

Answer 54

@midhun.madhu1987