Multiplication, hope I could help!
<span>●(a + b)^2 = (a +b) (a +b)
(a + b) (a + b) = a*a + a*b + b*a+ b*b = a^2 + 2ab + b^2
●(a – b)^2 (a - b) (a -b)
(a - b) (a -b) = a*a + -ab - ba + b*b = a^2 - 2ab + b^2
●(a - b)(a + b). =
= (a - b) (a + b) = a*a + ab - ba - b*b = a^2 - b^2
</span>
Answer:
51 rows
Step-by-step explanation:
Given
Length of bookmark = 20cm
Distance between beads = 4mm
Required
Number of rows of beads
First, the distance between the rows of beads must be converted to cm
if 1mm = 0.1cm
then
4mm = 4*0.1cm
4mm = 0.4 cm
This means that each row of beads is placed at 0.4 cm mark.
The distance between each row follows an arithmetic progression and it can be solved as follows;
Where 
(The last term)
(The first term)
(The distance between each row of beads)
n = ?? (number of rows)
Solving for n; we have the following;
becomes
DIvide both sides by 0.4
Add 1 to both sides
Hence, the number of rows of beads is 51
First find how much she makes per day for the 16 pages. Then divide it by the amount of hours she works to find her hourly average. So I guess you can use all these proportions.
From the given scenario is this particular item, the equation that can be derived for the distance traveled after x seconds is,
y = d₀ + (4)x
Substituting the known values x and y in order to solve for d₀ will give us an answer of,
13 = d₀ + 4(3)
d₀ = 1
Thus, the answer is 1 m.
