Math Help

Archive for December, 2005

Question: higher maths. The distance formula problem?

ok i am doing the distance formula and am having some problems and need help.

I have to find the distance between the pairs of points (3,-9) and (-2,3)

so the way i done it was

=square root of

(x2-x1)2 + (y2-y1)2

=square root of

((-2),-3) + (3-(-9)

= square root of

-5+12

=square root of -25 +144

= 119

but the answer says it should be the 169

=13

any one kno wher i am going wrong
my calculator says -25. mmmm wonder what thats about
wel i wont be squaring anythin else on my calculator.

Thanks everyone

Answer: you forgot the square sign in line 4
it should be written like this
={(-2)-(3)}^2 +{(3)-(-9)}^2
=(-2-3)^2+(3+9)^2
=25+144
=169
now the square root is 13 , so the answer is 13.

Algebra – Distance Formula Between Two Points Intuitive Math Help

Question: Hey, yes you, can you help me with these two math equations?

3 2/3 divided by 2 ?
and 10 1/2 divided by 2 7/8ths?
and can you help on this measuring inches problem so all my answers on this exam i am taking can be straight forward? It’s :Solve and give answer in simplest form: 5/2 times n = 48. So..n would equal to what? and what are the steps?
Hey, thanks very much

Answer: Hi,

3⅔ ÷ 2 =

11 . . 2
—- ÷ —- =
3 . . . 1

11 . . 1 . . . 11
—- x —- = —— = 1 5/6 <==ANSWER
3. . . 2 . . . . 6

10½ ÷ 2⅞ =

21 . . 23
---- ÷ ----- =
2 . . . 8

21 . . . 8
---- x ----- =
2 . . . 23

21 . . . 4 . . . 84
---- x ----- = ------- = 3 15/23 <==ANSWER
1 . . . 23 . . .23

5
---- n = 48
2

Multiply both sides by 2 to cancel out denominator and eliminate the fraction. then solve.

5n = 48(2)

5n = 96

n = 96/5 or 19 1/5 <==ANSWER

I hope that helps!!

Math Help : Solving Math Word Problems

Question: Math Ratios Question: Sam drove 100 miles at an average speed of 50mph. She then increased her average speed?

by 20 percent and drove 30 miles. what was her average speed for the entire journey, in mph?
Note: my wrong answer to this was 52.3mph. I multiplied 50×100 and 60×30 and added them together to get 6800. I then divided by 130 to get this answer. Help me please!
Please vote michiko best answer, thanks alot!

Answer: Average speed = Total Distance / total time.

We know total distance = 100 + 30 = 130 miles

Now for total time

time taken to cover 100 miles = Distance/Speed = 100/50 = 2 hrs

Now she covered the next 30miles at 20% more speed of 50mph = 120/100 * 50 = 60 mph

hence time taken to cover 30 miles at 60mph = distance / speed = 30/60 = 0.5 hrs

hence total time = 2 + 0.5 = 2.5 hrs

hence average speed = total dist/total time = 130/2.5 = 52 mph

Equivalent Ratios – YourTeacher.com – Math Help