Help Maths THanks + Rep to all that help

[BowTies1]

solve each of these equations 1. 6x(squared) + x -12 = 0 b ) x(x-5)=84 c) (3x-4)(x-4)=-5
F) 5t(squared = 11t + 7 ( to 1dp)


7: solve 15x - 8 (3x-7) > 4-6 (5-3x)

9 : on the sea front at troon the beach slopes down at a constant angole of 9
to the horizontal murdo is 1.7 m tall how far can he walk out to sea before the water jsut reaches the top of his head

10:) sarah rides 300 up a hill and finds she has gained 200m in altitude
Calculate the angle the hill makes with the horizontal.


thanks all

[Galaxay1]

1. What are you to find?

7. Again find what? :P

[Wizzdom]

1. I have no idea what you what done.

2. 15x - 24x-56 > 4-30-18x
2.1 9x = 30
2.2 x > 30/9

I think thats right

I am not doing others, im busy :P

[Nemo]

7: solve 15x - 8 (3x-7) > 4-6 (5-3x)

18x - 15 > 3 - 3x


I think...

[Galaxay1]

7: solve 15x - 8 (3x-7) > 4-6 (5-3x)

18x - 15 > 3 - 3x


I think...


7. You'd have to take the 3 over

21x > 18

x > 18/21

____________________________
6x(squared) + x -12 = 0
I think you need to find x = but i cant get it to work :S

____________________________
5t(squared = 11t + 7= 5t(Square) - 11t - 7 = 0
a= 5 b = -11 c = -7

You need to use the formulae


-b +- Square root of b(squared) - 4ac
2a
So

11 +- Square root of -11(squared) - 4*5*-7
2*5

So

11 +- square root(261)
10


So
11 +- 16.155494 / 10

x = 2.7155494 OR x= -0.5155494

So to 1DP

X = 2.7 or x = -0.5

[Nemo]

You'd have to take the 3 over

21x > 18

x > 18/21

____________________________
6x(squared) + x -12 = 0
I think you need to find x = but i cant get it to work :S

____________________________
5t(squared = 11t + 7= 5t(Square) - 11t - 7 = 0
a= 5 b = -11 c = -7

You need to use the formulae


-b +- Square root of b(squared) - 4ac
2a
So

11 +- Square root of -11(squared) - 4*5*-7
2*5

So

11 +- square root(261)
10


So
11 +- 16.155494 / 10

x = 2.7155494 OR x= -0.5155494

So to 1DP

X = 2.7 or x = -0.5oh yer, i forgot about that

[Galaxay1]

b ) x(x-5)=84

x(squared) -5x -84 = 0

then factorise (cant get it to work :S)

_________________________________
(3x-4)(x-4)=-5

3x(squared) - 12x - 4x + 16 + 5 = 0
3x(squared) - 16x + 21 = 0

then factorise

[Wizzdom]

b ) x(x-5)=84

x(squared) -5x -84 = 0

then factorise (cant get it to work :S)

_________________________________
(3x-4)(x-4)=-5

3x(squared) - 12x - 4x + 16 + 5 = 0
3x(squared) - 16x + 21 = 0

then factorise


Quadratic formula ;)

[BowTies1]

im struggling x(x-5) = 84 :S my next line of working i put

x(squared) - 5x - 84= 0 then i tried to facotrise but coudnt get it helop ?

[5,5]

Just put down B and say you thought it was multiple choice. xD

[Galaxay1]

BowTies try quad formula?

-b + Square root of x(squared)-4AC
______________________________________
2a

[BowTies1]

whats the formul;a in your calculater you put for calculating compound intrest fast :P isntead of going threw year 1 year 2 year 3 etcetc


yhe question is what is the fare price of the fare galsgow to london(26£ ) in 10 years if it rises by 2% per year

[Galaxay1]

26x1.02 to the power of 10

[H]

solve each of these equations 1. 6x(squared) + x -12 = 0 b ) x(x-5)=84 c) (3x-4)(x-4)=-5
F) 5t(squared = 11t + 7 ( to 1dp)
-----------------------------------------------------
6x(squared) + x -12 = 0
x = 1.3 recurring
x = -1.5
----------------------------------------------------
x(x-5)=84
x squared - 5x - 84
x = -7
x = 12
----------------------------------------------------
(3x-4)(x-4)=-5
4x squared -16x + 16 = -5
4x squared - 16x + 11
x =
x =

(my calculator just died soz!)

[sierk1]

im struggling x(x-5) = 84 :S my next line of working i put

x(squared) - 5x - 84= 0 then i tried to facotrise but coudnt get it helop ?

That is not so hard, since 84=12x7 (as you are of course well aware).
So x^2-5x-84=0 becomes (x-12)(x+7)=0 (hence x=12 or x=-7 as solution).