homework help...plzz help me i dont understand it?

Question

ok..i have a ton of homework due tomorrow. i really need help with my math homework. could u guys please help? dont give me the answer but explain the steps..plzzz
1. 12r-(8r-20)>12
2. 8m-2(2m+3)> or equal to 0
3. 4-5 (y-2)< or equal to -2(-9+2y)

plzz help me guys.. i really need your help. i will check every 5 mins. plzz xplain. i dont get it.

Answer 1

you have to use the distributive property.
like, on #1, you will have to distribute the negative into the parentheses, making the equation 12r-8r+20>12.
after that, you will want all of the variables on one side, and the numbers without variables on the other side of the inequality sign. so you will do the opposite of adding 20 in order to move it to the other side. you will subtract it from both sides. so the equation will be 4r>-8 (i am assuming you understood that i combined the like terms?)
then you will divide by the 4 to get the r totally by itself. the answer is r>-2

i hope that you will be able to figure out the other problems with that explanation! good luck!

ps. dont forget that when you divide by a negative, the inequality switches signs! and a heads up, but the person above me is wrong on #1. they missed a step. i dont mean to trash anybody, but i dont want you failing on your homework!

Answer 2

*Note 1: The main difference between "inequalities" and "equations"
is that if you multiply both sides by a "negative" number,
you have to flip the inequality the other way. Otherwise, it is solved the same as a regular equation.

** Note 2: Also, when you distribute a "negative" number by multiplying to drop the parentheses, you need to change the sign of the terms inside.

1. a. Combine like terms "r" (*see Note 2)
12r - 8r + 20 > 12
4r + 20 > 12
4r > -8
b. Divide by 4 to get r by itself
r > -2
check your work plug in "-1" for r and see if it works
(since "-1" > -2)
12(-1) - (-8 - 20) > 12
-12 + 28 > 12
16 > 12 this is true
You can also check if r "=" -2 makes
the "equation" true 12r - (8r - 20) "=" 12

2. a. distribute -2, and combine like terms "m"
8m - 4m - 6 > = 0 [**see Note 2]
4m - 6 > = 0
4m >= 6
b. Divide both sides by 4
m > = 6/4 or 3/2 = 1.5
Check your work
Pretend m = 3/2 and also check if m = 2 which is > 1.5

3. Distribute to remove parentheses, Combine like terms
4 - 5y + 10 < = 18 - 4y [** see Note 2]
14 - 5y <= 18 - 4y
Subtract 4y from both sides
and 18 from both sides:
-4 <= y
or
y >= -4
Check your work
Test if y = -4, and if y = -3 which is > -4

Answer 3

first you need to distribute the - to 8r and to 20 so 12r-8r+20>12. Then combine like terms (12r-8r) which is 4r+20>12. Then you need to get r by itself so -20 from both sides....so 4r>-8. Then divide both sides by 4 (get r alone) so r>-2.
2.) distribute the -2. So 8m-4m-6>or eq.0. Then Combine like terms...so 4m-6>or eq.0. Then add 6 to each side (so add the 6 to the -6 to cancel then add 6 to the 0. So then 4m>or eq to 6. Then divide by 4 to get m alone. So m>or equal to 3/2.....hope this helps....math sucks....any ?'s email me at [e-mail]

Answer 4

1 get rid of brackets
12r-8r+20>12
simplify to
4r+20>12
take the twenty onto the other side
4r>-8
divide by 4
r>-2

2 remove brackets
8m-4m-6=>0
simplify
4m-6=>0
take the 6 to the other side
4m=>6
divide by 4
m=>1.5

3 remove the brackets
4-5y+10=<18-4y
simplify
14-5y=<18-4y
take the y terms to the right hand side
14=<18+y
take the 18 to the LHS
-4=
hope that helps

Answer 5

1) 3y = 3 * y 2y = 2 * y -------------------- The LCD of 3y , 7y = 2 * 3 * y = 6y 4/3y = 8/6y 7/2y = 21/6y = = = = = = = = 2) 8x = 2 * 2 * 2 * x 12xy = 2 * 2 * 3 * x * y 6x = 2 * 3 * x -------------------------------- The LCD of 8x , 12xy , 6x is: 2 * 2 * 2 * 3 * x * y = 24xy (x + 1)/8x = (3xy + 3y)/24xy (3x - 1)/12xy = (6x - 2)/24xy 1/6x = 4y/24xy = = = = = = = = 3) x^2 - 4x - 5 = (x + 1) * (x - 5) x + 1 = x + 1 --------------------------------------... The LCD of x^2 - 4x - 5 , x + 1 is: (x + 1) * (x - 5) = x^2 - 4x - 5 6/(x^2 - 4x - 5) = 6/(x^2 - 4x - 5) 1/(x + 1) = (x - 5)/(x^2 - 4x - 5) = = = = = = = = 4) a - 5 = a - 5 a + 5 = a + 5 --------------------- The LCD of a - 5 , a + 5 is: (a - 5) * (a + 5) = a^2 - 25 a/(a - 5) = (a^2 + 5a)/(a^2 - 25) (a - 1)/(a + 5) = (a^2 - 6a + 5)/(a^2 - 25) = = = = = = = = 5) x^2 - 9 = (x + 3) * (x - 3) 2x + 6 = 2 * (x + 3) ----------------------------------- The LCD of x^2 - 9 , 2x + 6 is: 2 * (x + 3) * (x - 3) = 2(x^2 - 9) = 2x^2 - 18 2/(x^2 - 9) = 4/(2x^2 - 18) 1/(2x + 6) = (x - 3)/(2x^2 - 18)

Answer 6

1. This is the same as 12r + (-1)(8r-20) > 12. Distribute and simply.

2. Again, distribute the -2.

3. Ditto.

Hope this helps.

Answer 7

aight brown suga stop saying plzzz....
1. 12r-(8r-20)>12
4r-20>12
4r>32
r>8

2. 8m-2(2m+3)=> 0
8m -4m-6=> 0
4m-6=> 0
4m=>6
m=>(6/4)

3. 4-5(y-2)=< -2(-9+2y)
4-5y+10=< 18-4y
-5y+14=< 18-4y
-y=<4
y=< -4

Answer 8

For each, distribute the negative number over the parentheses.
Ex. 5t-4(3t+2)>1 becomes 5t-12t-8>1
Then collect like terms. Thus -7t>9
Then divide by the remaining multiplier. Thus t<-9/7. The > sign flips when dividing by a negative number.

Answer 9

Combine Like terms
Isolate the variable
Solve for the variable

Answer 10

12r-(8r-20)>12
(12r) -8r+20>12
-96rsquared 240r>12