Find the value of x.

x = 14

Step-by-step explanation:

Since they are similar triangles, their sides are proportional

12 : 15  :: 8 : x - 4

Product of extremes = Product of means

12 × ( x- 4 ) = 15 × 8

12x -48 = 120

12x = 120 + 48

12x = 168

x = 168/12

x = 14

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for