Answer:
The number of lower-priced speaker sold was 28
Step-by-step explanation:
The complete question is
An online store sells two types of speaker. The higher-priced speaker sells for $170 and the lower-priced speaker sells for $90. Last week the store sold four times as many lower-priced speaker as higher-priced speaker. Combined sales totaled $3,710. How many lower-priced speaker did it sell?
Let
x ----> the number of higher-priced speaker sold
y ----> the number of lower-priced speaker sold
we know that
Last week the store sold four times as many lower-priced speaker as higher-priced speaker
so
[tex]y=4x[/tex] ----> equation A
Combined sales totaled $3,710
so
[tex]170x+90y=3,710[/tex] ----> equation B
Solve the system by graphing
Remember that the solution is the intersection point both graphs
Using a graphing tool
The solution is the point (7,28)
see the attached figure
therefore
The number of lower-priced speaker sold was 28 and the number of higher-priced speaker sold was 7
