If 57 is added to a number, it will be 4 times as large as it was originally. Find the number.

19

Step-by-step explanation:

X will refer to the number.

X+57( the number added to the original.)=4x. (x time 4)

X+57=4x.

Subtract x from both sides to get the variable on one side.

(X+57)-x =(4x)-x

57=3x. You would then divide by 3 on both sides to again get integer isolated.

57/3=3/3x.

57/3=19. 3/3=1.

19=x.

step-by-step explanation:

part a. the differences are decreasing, so we know the sequence is not arithmetic. the ratios are constant (=3/4), so we know the sequence is geometric.

part b. from part a, we know the common ratio is 3/4, so each term is 3/4 of the one before. the initial term is the number of gallons at h=1.

g[h] = (3/4)·g[h-1]

g[1] = 384 . . . . initial value required for a recursive definition

part c. the general formula for a geometric sequence is

a[n] = a[1]·r^(n-1)

we have a[1] = 384, r = 3/4, and the term number given by h. the formula that follows is

g[h] = 384·(3/4)^(h-1)

part d. filling in the value and doing the arithmetic, we have

g[12] = 384·(3/4)^11 ≈ 384·0.042235136 ≈ 16.2183 . . gallons

part e. each gallon is 4 quarts, so

16.2183 gal × 4 qt/gal = 64.8732 qt