An online store sells two types of speaker docks for smartphones. The higher-priced speaker dock sells for $170 and the lower-priced speaker dock sells for $90. Last week the store sold four times as many lower-priced speaker docks as higher-priced speaker docks. Combined sales totaled $4,770. How many lower-priced speaker docks did it sell?

9

Step-by-step explanation:

Let us represent

Low priced = x

High priced = y

An online store sells two types of speaker docks for smartphones. The higher-priced speaker dock sells for $170 and the lower-priced speaker dock sells for $90. Combined sales totaled $4,770.

170x + 90y = $4770

Last week the store sold four times as many lower-priced speaker docks as higher-priced speaker docks.

4x = y

Substitute 4x for y

170x + 90y = $4770

170x + 90(4x) = $4770

170x + 360x = $4770

530x = $4770

x = 4770/530

x = 9

The number of lower-priced speaker docks it sold was 9

b) 36

step-by-step explanation:

18 times 2 is 36