I need some help with my algebra work?

Question

umm ok if you can please explain a little how everything works out and such

4=9b-2(4b-1)

yeah that question has been bothering me so i skipped it so im right back to it. thank you :)

Answer 1

4 = 9b - 8b + 2

first you have to multiply the parantheses because of the rules of operation, then you can simplify and solve for "b"

4 = b + 2

now that you have simplified, you can solve for "b" by subtracting 2 from both sides

2 = b

now that b equals 2, check your work by going back to the top and replacing each "b" with a 2

4 = 9(2) - 2(4(2)-1) or 4 = 18 - 2(8-1) or 4 = 18 - 14

Answer 2

It looks scary but it's not. you have to find what -2(4b-1)is so you would end up with -8b+2, the reason for the plus 2 is a negative times a negative = a positive (-2X-1)=+2. Then you plug in the answer you just got (-8b+2) into the -2(4b-1) spot, and now you have 4=9b-8b+2. Now you add like terms so 9b-8b=1b or b (they are the same) and you move the 2 to the left side by changing it to -2 so 4-2=2. The equation you have now is 2=1b or b. so 2 equals b. Don't let alot of numbers and letters scare you. Just take it slowly piece by piece like a puzzle and you'll do fine.

Answer 3

4=9b-2(4b-1)
remove the parenthesis
4=9b-8b+2
4=b+2
subtract 2 from both sides
4-2=b+2-2
2=b or b=2
check:
since b=2
therefore replace b with 2 in the equation.
4=9(2)-2[4(2)-1]
4=18-2(7)
4=4

Answer 4

The way you have it written it should work like this
mutiply the -2 across the 4b-1
4=9b-8b+2
4=b+2
subtract 2 to each side to isolate the b
-2+4=b+2-2
2=b

Answer 5

Break down the bracket first.

So 4= 9b-2(4b-1) becomes 4 = 9b - 8b + 2 Note the bracket is removed and the -2(4b-1) has become -8b+2.

Next

4 = 9b-8b +2 becomes 4 = b +2


4-2 = b +2 -2
2 = b

OK ?

Answer 6

I tutor students in math and how I get them to remember these problems is this: Remember PEMDAS (say it out loud many times so it sticks) and this is your basic order of operations. P=parenthesis (do everything within a parenthesis that you can) E=exponents (multiply out any exponents) M=multiply D=Divide (Multiply and divide from left to right) A=Add S=Subtract (add and subtract from left to right).

The problem you are asking about goes like this

parenthesis = multiply the -2 by 4b (-8b) and the -2 by -1 (neg times a neg is always positive) so you would get +2

so now you are at 4=9b-8b+2

Exponents = We don't have any exponents so we move to the next step

Multiply and Divide= none so move on

Add and Subtract(from left to right)

so you see we now take 9b-8b (because they are like terms) and you end up with 1b or just b.

now we have 4=b+2

We want to solve for b so we need to get rid of the two. In order to do this we have to make that 2 a 0. What would we subtract from 2 to make it zero you ask? 2 of course. But in algebra if you do something to one side of an equation, you have to do it to the other so we have to subtract 2 from the 4 too (god this is so much easier to explain with scratch paper).

4-2=b+2-2
2=b

Answer 7

Okay, you're solving for b: I'll put it in step-by-step how it works, okay?

4=9b-2(4b-1) (original problem)
4=9b-8b+2 (you multiply -2 (if you have a minus sign in front of a set of numbers in parantheses, you treat the number there as a negative number. -2 x 4b = -8b, and -2x-1 = 2 since a negative times a negative equals a positive).
4=1b+2 (subtract 8b from 9b)
2=1b or 2=b (same answer. To deal with the 2 on the right side of the equation, you subtract it from the right side of the equation. BUT - key thing to remember in algebra - if you add, subtract, multiply, or divide on one side to 'get rid of something'...you MUST do it to both sides...so if you wrote it out, you're last step would be 4-2=1b+2-2.)

That help?

Answer 8

4=9b-2(4b-1)

first Multiply paranthesis or brackets -2*4b and -2*-1
which gives
=>4=9b-8b+2

then shift 2 to left side by changing the sign from + to - and
subtract 8b from 9b which gives
=>4-2=b

then subtract 2 from 4, whcih gives,
=>2=b

which means
=>b=2.


Have a nice day.

Answer 9

The first thing you have to do is get rid of the parentheses. Multiply whats inside the parentheses by whats outside them so you get 4 = 9b - 8b + 2. Now you have to combine like terms which would be anything standing alone and anything with a variable (b) and you will get 4 = b + 2. Subtract the 2 from the right side and add it to the left side to get 2 = b, which is your answer. I hope this helps!

Answer 10

4 = 9b - 2(4b - 1)
4 = 9b - 8b + 2
4 - 2 = 9b - 8b
2 = b
b = 2