Easy math assignment - 10k SAMP cash as reward. (updated 17:04)

[Ben.]

2)two bikers (Bob and Mary) were racing on a 150km long track. Bob reached the finish 20 minutes before Mary and Bob's speed was 5km/h faster then Mary's speed. how many hours it took for Bob to pass the track?

Explain how you reach the outcome of your math.

3)You have an square looking metal plate. If you cut off 3 cm from the edge you will get an metal plate with area 10cm (squared) (s=10cm)
question: What were the measures of the plate in the beginning

Explain how you reach the outcome of your math.

3)
On the theory of trial and improvement:
Metal plate is x²

x²-3=10cm²
therefore...
x-1.73205080...=3.163377660168...
x=3.163377660168...+1.73205080...
x=4.895428...cm
x=4.90cm(to 3 s.f)

[Gimli]

3)You have an square looking metal plate. If you cut off 3 cm from the edge you will get an metal plate with area 10cm (squared) (s=10cm)
question: What were the measures of the plate in the beginning

Explain how you reach the outcome of your math.

(x - 3)x = 10
x^2 - 3x = 10
x^2 - 3x - 10 = 0
D = 9 - (-40) = 49
X1 = (3-7)/2 = -2 (can't use this)
X2 = (3+7)/2 = 5

Edge 1: 5
Edge 2: 5-3 = 2

5*2 = 10cm

So, in the beginning both edges were 5cm.

[kaslu1000]

x - brother, y - sister

x+y = 50
2x+x = 30 //10 years ago - take away 20 from the result
3x = 30

x = 20+10
y = 10+10

brother - 30, sister - 20

10 years ago the brother was 20 and the sister was 10

I am inteligent too but not in this problems

[Seskom]

(x - 3)x = 10
x^2 - 3x = 10
x^2 - 3x - 10 = 0
D = 9 - (-40) = 49
X1 = (3-7)/2 = -2 (can't use this)
X2 = (3+7)/2 = 5

Edge 1: 5
Edge 2: 5-3 = 2

5*2 = 10cm

So, in the beginning both edges were 5cm.

thats correct, thanks

[Ben.]

Oh shit! I really need to learn to read questions...I took 3 off everything I think :S