Can soemone help me with a math question 4 school?

sarahsaurus • 18 October 2012 at 8:09 PM

Im doing my math and need help on these two:

What is 2003.67 written in scientific notation?
(I dont know what to do with the stupid decimal!)

7+x=10
2y=8

(x4)+7-(yx)= ?

puppyloverlauren • 18 October 2012 at 8:13 PM

@sarahsaurus

for #2 isn't x=3 and y=4 ?

sarahsaurus • 18 October 2012 at 8:14 PM

@puppyloverlauren

uh... yeah...

cubexline • 18 October 2012 at 8:14 PM

For the second one, you just subtract 7 from both sides so the answer is x=3.
The third one you would just divide 2 on both sides: 2y/2=8/2 so y=4

Im working on the first one now.

Edit: I have the answer for the first one, but not sure how to explain it lol

sarahsaurus • 18 October 2012 at 8:17 PM

@cubexline yeah but the problem under that.

cubexline • 18 October 2012 at 8:18 PM

@sarahsaurus: Not sure how to work that one... Sorry

sarahsaurus • 18 October 2012 at 8:19 PM

@cubexline yeah me either. i hate 6th grade... -_-

twilight_raptor • 18 October 2012 at 8:22 PM

@sarahsaurus for the first one you can move the decimal next to 2 so it would be 2.00367 and since you moved it (backwards) you have to add 10 to the power positive (the number of times you moved the decimal). here you moved it 3 places backwards so the answer is
2.00367 x 10^3 (let me know if you don't get it 😊)

seems like you have to solve for x here:
7+x=10

First isolate x. to do that add -7 on each side to cancel out the 7 on the left (what you add to one side you have to do so for the other side too):
7 -7 +x = 10 -7
x= 3

Solve for y:
2y=8

first isotale y. to do that divide each side by 2:
(2y)/2= 8/2
(2 cancels out on the left)

y=8/2=4

Zac • 18 October 2012 at 8:24 PM

2003.67 = 2.00367 x 10^3

For the last equation, what do you want to do with it? Did you want to find its values with the above calculated values of x and y? If so the answer is:

(x4)+7-(yx)= ?
= (4*3)+7-(4)(3)
= 12 + 7 -12
= 7

sarahsaurus • 18 October 2012 at 8:25 PM

@twilight raptor

Soooo.... you just move the decimal to the lead number and take the number since there are no zeros at the end and add times ten to the third? wow. i feel stupid. 😋

Thanks!

twilight_raptor • 18 October 2012 at 8:29 PM

@sarahsaurus edited my first post >< made a mistake with the first one. its supposed to be 10^+3 not -3

kurochi-akuma • 18 October 2012 at 8:49 PM

@sarahsaurus

What is 2003.67 written in scientific notation?
(I dont know what to do with the stupid decimal!)

2.00367 * 10^3

7+x=10

Subtract both sides by 7 so you end up with x = 3.

2y=8

Divide both sides by 2 so you end up with y = 4.

(x4)+7-(yx)= ?

Fill in with the answers you got(assuming the two problems are connected):

(3(4)) + 7 - (4(3)) = a
12 + 7 - 12 = 7 <- Answer

Dunno if that helps or not. o3o

Or if you got it answered already. Hehe. ^^;

spirithawk • 18 October 2012 at 8:58 PM

@sarahsaurus Lol, I'm only in 4th Grade. 😋 This is the only one I actually understand. xD

x = 3.