Hi,
I think this is the table, correct?
Number of Tubes 3 5 7
Cost ($) 12 20 28
we can calculate the prize as the number of tubes multiplied by 4:
3*4=12
5*4=20
7*4=28
which means that one tube costs 4 dollars!
However, in the store A two tubes cost 7, which means that one costs half of this -3.5
So Store B is more expensive (4 dollars per 4 rather than 3.5 as in Store A).
Answer:
6t+3
Step-by-step explanation:
If t represents the number of tens, then 6t is six times the number of tens. 3 more than that is ...
6t+3
X=width of a coccer pitch
2x-20=length of a soccer pitch
Area (rectangule)=length x width
We suggest this equation:
x(2x-20)=6000
2x²-20x=6000
2x²-20x-6000=0
x²-10x-3000=0
We solve this quadratic equation:
x=[10⁺₋√(100-4*1*-3000)]/2=[10⁺₋√(100+12000)]/2=
=(10⁺₋110)/2
we have two solutions:
x₁=(10-110)/2=-50, invalid solution.
x₂=(10+110)/2=60
x=60
2x-20=2(60)-20=120-20=100
Solution: the length is 100 m, and the width is 60 m.
To check:
Area=100 m*60 m=6000 m²
The twice of width is =2(60 m)=120 m,
20 m less than twice its width is: 120 m-20 m=100 m=the length.
