Thread: Homework stuff

16
3-4q=10q+10
(add 4q to both sides) --> 3=14q+10
(take away 10 from both sides) --> -7=14q
(divide by 14) --> -0.5=q

18
5t-9=-3t+7
(add 3t to both sides) --> 8t-9=7
(add 9 to both sides) --> 8t=16
(divide by 8) --> t=2

20
3/4n+16=2-1/8n
(add 1/8n to both side) --> 7/8n+16=2
(take away 16 from both sides) --> 7/8n=-14
(multiply 14 by 8 and then divide by 7 --> n=-16

22
8=4(3c+5)
(multiply the brackets out --> 8=12c+20
(take away 20 from both sides) --> -12=12c
(divide by 12) --> -1 = c

24
6(r+2)-4=-10
(multiply out the brackets) --> 6r +12 -4=-10
(simplify) -->6r+8=-10
(take away 8 from both sides) --> 6r=-18
(divide by 6) --> r=-3

26
4(2a-1)=-10(a-5)
(multiply out the brackets) --> 8a-4=-10a+50
(add 10a to both sides) --> 18a-4=50
(add 4 to both sides) --> 18a=46
(divide both sides by 18) --> a=2.56 (3 significant figures) Weird answer

28
3(1+d)-5=3d-2
(multiply out the brackets) --> 3+3d-5=3d-2
(simplify) --> 3d-2=3d-2
d=0

Check it over though, it's 3am so i could have made a mistake. To check, take the values of the unknowns listed and plug them back into the equation, if it works, that's your answer.

20 was the one giving me problems.

Here's what I got:

16) -.5=q
18) t=2
20) 22.4=n
22) -1=c

Edit:

I originally got -16 for 20, but i forgot to add the - sign, so when i went to check it, it didn't match. So I did it differently, and got 22.4, which was also wrong.

I almost did that again for 24.

Thanks.

Edit:

Wait, wouldn't 28 be 0=0?

3(1+d)-5=3d-2
3+3d-5=3d-2
3d-3d=-2+5-3
0=0

indeed you were right Demo...

You forgot to divide by 0 a couple times. Other than that you were correct.


http://c2.api.ning.com/files/ZoC66g*...videbyzero.jpg

Wait why do you divide? o.o

The whole point of the exercise is to find out the values of the unknowns, the letters. Proving that 0 = 0 really isn't needed, the correct answer is d = 0.

Oh! Makes sense!

I don't get it. but I have no idea if what I'm getting is the answer or not.

Anyone wanna help me with my math homework? Evaluate the antiderivative of this: The integral of (e^tan(x) / (1-sin^2(x))) * dx... Okay don't actually...