Thread: Equations

Thanx for the help guys.

I'm kind of tired, so check my answers with my solutions and make sure i picked the right one

1)
Ans: C

Solution:
x^2 + 2x - 24 = 0
=> (x + 6)(x - 4) = 0
=> x = -6, x = 4

2)
Ans: B

Solution:
x^2 + 4x - 3 = 0
=> x = [-4 +/- sqrt(16 + 12)]/2 = -2 +/- sqrt(7)

3)
Ans: E

Solution:
x^2 - 8x + 5 = 0
=> x = [8 +/- sqrt(64 - 20)]/2 = 4 +/- sqrt(11)

4)
Ans: D

Solution: x = 0 or x - 5 = 0
=> x = 0, x = 5

5)
Ans: D

Solution: x - 2 = 0 or 2x - 5 = 0
=> x = 2, x = 5/2

6)
Ans: A

Solution:
x^2 + 4x - 21 = 0
=> (x + 7)(x - 3) = 0
=> x + 7 = 0 or x - 3 = 0
=> x = -7, x = 3

7)
Ans: B

Solution:
x^2 = 196
=> x = +/- sqrt(196) = +/- 14

8)
Ans: D

Solution:
9 = (n^2 - 3n)/2
=> 18 = n^2 - 3n
=> n^2 - 3n - 18 = 0
=> (n - 6)(n + 3) = 0
=> n = 6, n = -3
=> n = 6, since we can't have -3 sides

I will do the rest soon

You live around the same country as me!!! its only around 10, long day or what? lol

Originally Posted by Soldja Soul3ss

You live around the same country as me!!! its only around 10, long day or what? lol

it's been more like a long two days, i slept like 2 hours last night

9)
Ans: D

Solution:
let the width of the deck be x
let the area of the deck and pool be A

then the new length is 40 + 2x
the new width is 25 + 2x

=> A = 1584 = (40 + 2x)(25 + 2x)
=> 4x^2 + 130x - 584 = 0
=> 2x^2 + 65x - 292 = 0
=> x = [-65 +/- sqrt(65^2 + 4(2)(292))]/4
=> x = 4 .........i only took the positive answer


10)
Ans: C

Solution:

let the width be x
then the length is x + 5

=> A = 500 = x(x + 5)
=> x^2 + 5x - 500 = 0
=> x = [-5 +/- sqrt(25 + 2000)]/2 = 20

It doesnt tell which ones are wrong, it just does it and shows me my score on a different page. Wish i knew also, but as long as i get a 80% or higher i dont have to do 3 more tests. So 9/10 is a blessing from god in my eyes. Unfortunately i have 6 more to do total from being wrong on 2 tests making you guys here a little bit busy ^^, maybe 9 more after i post this next thread in the right place lol. Unless you wanna stay up to help a brotha out rofl. But i suggest you go to sleep .

all my solutions are correct. i double checked. maybe you clicked the wrong letter or something

and that's stupid, why wouldn't it tell you which you got wrong. shouldn't a student be able to see where he is weak and thus prepare for tests based on that?

Well that test is the first assignment of teh lesson, if you dont pass it with 80% or higher you have to do 3 more and there are no practices, just very non detailed lessons on the type of algebra. But i guess its best to just not go on about it off topic kinda, the admin is upset with me already lol.