math question help?

Question

Hi i was just wondering if someone could help me out, i have a test on these types of questions soon and am pretty confused. it's an algabra question. i can get the answers somtimes but i want the steps on how to get it.

Okay if A=3, b=2 and C=-6 can you help me with these problems


9a + 3-2a

8 -5b - 1

-4b -6 + 20b-3

2- (-8c) + 24-7c


please help me out, not just the answers but how to get them thank you for your help

Answer 1

All you have to do is substitute what a,b,&c equal.Here's an example:

9a+3-2a
(9*3)+3-2(3)
27+3-6
30-6
24


8-5b-1
8-(5*2)-1
8-10-1
-2-1
-3

2-(-8c)+24-7c
2-(-8*-6)+24-(7*-6)
2-(48)+24-(-42)
-46+66
20

Does that help any??

Answer 2

First of all you have to substitute what is a,b and , c for example the first one:

9a+3-2a you substitute as following:
First a:
(9 x 3) + 3 - (2 x 3)
You must remeber that you have to separate in terms and the only signs that separate terms is the + and the - signs so everytime you have equations like:
9a+3-2a you know that the first thing you have to do is multiply the 9a which is 9 x 3 and on the other hand multiply -2a which in this case is - (2 x 3). Then afterwards you do all the multipications that are in the equation you do what is all the sums and the subtractions.
So know remebering all what I told you in steps:
1 - Substitute the letters with the numbers given.
2 - Solve all the multiplications.
3 - Solve the + and the -.

Now looking to the equations you gave us:

9a+3-2a
(9x3) + 3 - (2x3)
27 + 3 - 6
24

Now the second example:
8-5b-1
8 - (5x2) - 1
8 - 10 - 1
-3

The third example:
-4b-6+20b-3
(-4 x 2) - 6 + (20 x 2) - 3
-8 -6 + 40 -3
23


The last example:
2-(-8c)+24-7c
2 - (-8 x -6) + 24 - (7 x -6)
2 - (48) + 24 - (-42)
^
Here you have a tricky one!!
when you have this kind of questions you must know that here the - is multiplying the whole equation. I don't know if you have learned this but remeber that:

+ multiplied by + = +
A positive number multiplied by a positive number will give a positive number.

A negative number x a negative number will give a positive number.
- x(times) - = +

A negative number times a positive number will always give a negative number.
- x + = -

So going back to the equation to the last thing we were doing:
2 - (48) + 24 - (-42)
2 - 48 + 24 + 42 ( because minus times minus is +)
the final result is 20.

That's all and I hope it was useful this long explanation. Wish you luck in your test.

Answer 3

It could be that you're having trouble with the signs.
Always keep in mind that (-1)*(-1)=1

or order of operations. Always to the multiplications or divisions before the additions or subtractions.

so for 9a+3-2a
write it out as
(9*3)+(3)-1*(2*3)
27+3-6
24

Now the last one
2-(-1*8*(-1*6))+24-1*(7*(-1*6)
multiply
2-48+24+42
do the adds and subtracts
=20

Answer 4

Since a,b,and c are known, just plug them in and multiply by the factors given.

(9x3) + 3-(2x3)

27+3-6

30-6

24

It is all a matter of grouping you factors so the problem is done in the right order.

Answer 5

1 ) 24
2) -3
3) 23
4) 20

Answer 6

1.9(3)+3-2(3)=24
2.8-5(2)-1=-3
3.-4(2)-6+20(2)-3=23
4.2-(-8)(-6)+24-7(-6)=20