$1.\\\sqrt{81}=9\ because\ 9^2=81\\\\\fbox{D.}\\\\2.\\55\cdot9=495\\\\\fbox{A.}\\\\3.\\8^3=8\cdot8\cdot8=512\\\\\fbox{D.}\\\\4.\\4^3=4\times4\times4\\\\\fbox{D.}\\\\5.\\512=8\cdot64\\\\\fbox{A.}\\\\6.\\23^2=23\cdot23=529\\\\\fbox{A.}$

7 0

3 years ago

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The graph shows the cost of some taxi journeys work out a formula for c in terms of n

Vitek1552 [10]

Answer:

$c=\frac{3}{5}(n)+2.5$

Step-by-step explanation:

see the attached figure to better understand the problem

Let

c -----> the cost of some taxi journeys

n ----> the number of miles

we know that

The graph is a line

The equation of a line in slope intercept form is

$c=m(n)+b$

where

m is the slope

b is the c-intercept (value of c when the value of n is equal to zero)

Observing the graph we have the points

(0,2.5), (5,5.5)

Find the slope

The formula to calculate the slope between two points is equal to

$m=\frac{c2-c1}{n2-n1}$

substitute the values

$m=\frac{5.5-2.5}{5-0}$

$m=\frac{3}{5}$

we have

$b=2.5$ -----> because the point (0,2.5) is the c-intercept

substitute in the equation of slope-intercept form

$c=\frac{3}{5}(n)+2.5$

4 0

4 years ago