Answer: Well, I thought about it and I was like, Well 813 right? Then I realized the question and was like: Nvm lol (Hope you find the answer!)
It might be 0.133928571.....? I am unsure though. Sorry if this doesn't help
We can factor this by using grouping. Take the leading coefficient and multiply it by the constant. In this case we get 5*-7 = -35.
Now we need 2 numbers that add to 2 and multiply to be -35. The numbers are -5 and 7.
So split the 2r into these two terms and group.
(5r^2 - 5r) + (7r - 7)
Factor both groups.
5r(r-1) + 7(r-1)
The factors of (r-1) can be added together to get the answer.
(r-1)(5r+7)
Step-by-step explanation:
£480 = 120% (after adding the 20% VAT).
we want to know how much 100% is.
he do we get from 120% to 100% ?
first the formal long way
£480 = 120%
1% = 120%/120 = 480/120 = £4
100% = 1% × 100 = 4×100 = £400
once you understand this mechanism, you can apply the direct shortcut :
£480 / 1.2 = £400
as a multiplication with 100/120 is the same as a division by 120/100, which is 1.2.
and what we did at the beginning in long form was nothing else than
£480 × 100/120 = 480 × 10/12 = 480 × 5/6 = £400
Answer:
Dimensions: 
Perimiter: 
Minimum perimeter: [16,16]
Step-by-step explanation:
This is a problem of optimization with constraints.
We can define the rectangle with two sides of size "a" and two sides of size "b".
The area of the rectangle can be defined then as:
This is the constraint.
To simplify and as we have only one constraint and two variables, we can express a in function of b as:
The function we want to optimize is the diameter.
We can express the diameter as:
To optimize we can derive the function and equal to zero.
The minimum perimiter happens when both sides are of size 16 (a square).
