1.2, 3, 7.5, 18.75, which formula can be used to describe the sequence? a. f(x) = 1.2(2.5)^x – 1 b. f(x) = 2.5(1.2)^x – 1 c. f(x) = 1.2(2.5)^x d. f(x) = 1.2(2.5)^x

The formula that could be used for showing the sequence is option A.

The sequence should be geometric which means the first term 1.2 and the common ratio is = 2.5.

Now The explicit formula should be

Now

Here a[1] = 1.2

and r = 2.5,

So, the formula is

Learn more about the sequence here: link

  a.  F(x) = 1.2(2.5)^(x – 1)

Step-by-step explanation:

The sequence is geometric with first term 1.2 and common ratio 3/1.2 = 2.5. The explicit formula for such a sequence is ...

  a[n] = a[1]·r^(n-1)

For a[1] = 1.2 and r = 2.5, and using x as the term number, the formula is ...

  F(x) = 1.2·2.5^(x-1) . . . . . matches selection A

a.   we have two

lines:   y = 4-x   and  

y = 8-x^-1

given two simultaneous equations that are both to be

true, then the solution is the points where the lines cross. the intersection is

where the two equations are equal. therefore the solution that works for both

equations is when

4-x = 8-x^-1

this is where the two lines will cross and that is the

common point that satisfies both equations.

b.   4-x = 8-x^-1

  x           4-x       8-x^-1

-3           7        

8.33

-2           6         8.5

-1           5         9

  0           4        

-

  1           3        

7

  2           2        

7.5

  3           1         7.67

the table shows that none of the x values from -3 to 3 is

the solution because in no case does

4-x = 8-x^-1

to find the solution we need to rearrange the equation to

find for x:

4-x = 8-x^-1

multiply both sides with x:

4x-x^2 = 8x-1

x^2+4x-1=0

x= -4.236, 0.236

therefore there are two points that satisfies the

equation.

find y:  

x=-4.236

y = 4-x   = 4 – (-4.236)

= 8.236

y = 8-x^-1 =   .236)^-1

= 8.236

x=0.236

  y = 4-x   = 4 – (0.236) = 3.764

y = 8-x^-1 =   8-(0.236)^-1

= 3.764

thus the two lines cross at 2 points:

(-4.236, 8.236) & (0.236, 3.764)

c.   to solve

graphically the equation 4-x = 8-x^-1

we would graph both lines: y = 4-x   and   y

= 8-x^-1

the point on the graph where the lines cross is the

solution to the system of equations.

just graph the points on part b on a cartesian coordinate

system and extend the two lines.   the

solution is, as stated, the point where the two lines cross on the graph.

step-by-step explanation:

mark brainliest!