word problem math help!!!!!!!!!!?

Question

explain clearly on how to solve???
use the variable N???....

1)The sum of two numbers is 18.If the larger number is twice the smaller number find the two numbers...
small no.= x so smaller number is 18???
bigger no= 2x-18 bigger number 12???
solution?
x+2x-18=18
3x+18+18 x=12 18-12=6 6x3+18???x=18
3x/3+36/3
is this right or what??

2) One number is one more than 3 times the smaller number.Their sum is 69.Find the numbers.haha still use the small...bigger representation like mine.(cant understand this?!!)

3)The larger of 2 no. is 12 more than half the smaller number find their number if their sum is 30.

4)Find 2 numbers whose sum is 31,one of which is 5 less than twice the other.

sorry if it's to many i just cant understand word problems...
good luck and have a nice day

Answer 1

x + y = 18
x = 2y
2y + y = 18
3y = 18
y =6
x = 12

B = 3 S + 1
B + S = 69
3 S + S + 1 = 69
4 S = 68
S = 17
B = 52

L = S /2 + 12
L + S = 30 . . . . . . L = 30 - S . . . substitute
30 - S = S/2 + 12
3/2 S = 30 -12 =18
S = 18 ( 2/3) = 12
L = 18

x + y = 31
x = 2y - 5 . . . . subtitute
2y - 5 + y = 31
3y =36
y = 12
x = 19

Answer 2

1) if the two numbers are x and 18-x
then the eq is 2x = (18 - x)
3x = 18, x = 6 number = 6,12=(2x6)

2) 3x + 1 = (69 - x)
4x = 68
x = 17 number = 17 and 52= (3x17+1)

3) 1/2 x + 12 = 30 - x
x + 24 = 60 - 2x
3x = 36
x = 12 number = 12 and 18 = ( 12/2 + 12)

4) 2x - 5 = 31 - x
3x = 36
x = 12 number = 12 and 19 (2x12-5)

Answer 3

1) n + (2n) = 18
3n = 18
n = 6 2nd # = 12

2/3) n + (.5n + 12) = 30
1.5n + 12 = 30
1.5n = (30 - 12)
n = 28/1.5
n = 12 2nd # = (6 + 12) = 18

4) n + (2n - 5) = 31
3n - 5 = 31
3n = 36
n = 36/3
n = 12 2nd # = (12*2) -5 = 24 - 5 =19



I hope you understood my work, it's a lot harder to explain when I'm not verbalizing it!! ; )