Just some math questions :)?

Question

Man I suck at these. Thanks for any help!!!! <3333333

1. Joe is 5 years older than Sally. In 15 years Joe will be 3 times as old as Sally is now. How old is Sally now

2. The length of a rectangle is 3 more than twice its width. The perimeter is 48 feet. Find the width.

3. Fifteen more than four times a number is 6 more than five times the number. Find the number

Thanks for everyone that helped!!!!!!!

Answer 1

s = sally's age now
s+5 = Joes age now
s+20 = Joe's age 15 years from now
s+20 = 3s
2s = 20
s = 10 = Sally's age now

w = width
2w+3 = length
w+w+2w+3+2w+3 = 6w+ 6 = perimeter
6w+6 = 48
6w = 42
w = 7

x = number
4x+15 = 5x+6
x = 9

Answer 2

1.) If Joe is 15, and he gets 15 more years, he'll be 30. Divide by 3, and Sally was 10 years old. Add 5 more years, and that's 15. So Sally is 25 after the 15 years.

2.) Let the Width be 7 and the Length be 17. Times them both by 2 and its 14 and 34, so plus them together and its 48. You figure this out by Multiplying the width by 2, which is 14, then add 3 more and its 17. So that's our length. Then the width is just 7 alone, and you gotta times them by two since a rectangle is the same size on opposite sides.

3.) Great..this one sounds fun. Do 9 x 4, which turns out to be 36, then add 15 and its 51. To find out the other one, minus the number by 6, which is then 45, then divide it by 5, and its 9, which is the number we used on the first equation.

All of these problems are trial-and-error. You guess different numbers by plugging them in. Really annoying as crap...took me about 10 minutes to do these.

Answer 3

Hi,


1. Joe is 5 years older than Sally. In 15 years Joe will be 3 times as old as Sally is now. How old is Sally now

age........age in
now........15 yrs
----------------------
x+ 5..........x+20..Joe
x................x+15..Sally

If in 3 yrs Joe will be 3 times as old as Sally is now, then:
x+20 = 3x
x+20 = 3x
20 = 2x
10 = x so Sally is 10 years old. <== ANSWER

2. The length of a rectangle is 3 more than twice its width. The perimeter is 48 feet. Find the width.
If x = width then 2x+3 = length, which is 3 more than twice the width. Since P = 2L + 2W:

48 = 2(2x+3) + 2x
48 = 4x + 6 + 2x
42 = 6x
7 = x <== This is the width.


3. Fifteen more than four times a number is 6 more than five times the number. Find the number

15 + 4x = 6 + 5x
15 = 6 + x
9 = x <== ANSWER

I hope that helps!! :-)

Answer 4

1) First sentence: Joe=5+Sally
Seconde sentence : (Joe+15)=3 x Sally
If we put first one to second sentence (Sally:S, Joe:J)
S+5 + 15=3S
2S = 20
S= 10 years old

2) If x is width: (you know perimeter is 2 x (length + width)
48 = 2(2x+3) + 2x
48 = 4x + 6 + 2x
42 = 6x
7 = x


3) 4A + 15 = 6 + 5A
A = 9

THAT'S ALL...

Answer 5

2.
L=2W+3
48=2L+2W

since L = 2W + 3
in the equation 48 = 2L+2W
replace the L with 2W+3

48=2(2w+3)+2w
48=4w + 6 +2w
48=6w + 6
42=6w
w=7

Answer 6

1:

J = S + 5
J + 15 = 3S

J = 3S - 15

3S - 15 = S + 5
2S = 20
S = 10

Sally is 10
(Joe is 15, so in 15 years he'll be 30. 30 = 3 x 10)

2:

L = 2W + 3
P = 2L + 2W = 48

2(2W + 3) + 2W = 48
4W + 6 +2W = 48
6W + 6 = 48
6W = 42
W = 7

The width is 7

3:

4N + 15 = 5N + 6
N = 9

Answer 7

Sally is 10

width is 7 feet

9

Answer 8

Ok i am not a math person but i thought i would try it out would the answer to number 1 be that Sally is 25 years old?

Answer 9

here's something that may help.
Go to purplemath.com
and click on mathnerds.
They help with everything!
They are like online tutors for people like you.

Answer 10

Get a tutor when you go to college or take your SATS oh trust me there wont be anyone there to help you!

GET A TUTOR.