PP-T2-DS154

[little8]

154. 15741-!-item-!-187;#058&010784
To install cable television in a home, a certain cable company charges a basic fee of $30 plus a fee of $20 for each cable outlet installed in the home. How much did the cable company charge the Horace family for installing cable television in their home?

(1) The cable company installed three cable outlets in the Horace family home.

(2) The amount that the cable company charged the Horace family for installing cable television in their home was equivalent to an average (arithmetic mean) charge of $30 per cable outlet installed.

D
請教一下(2)劃粗體的部分是什麼意思?

[amazingslim]

裝第四台收基本費30+each插座費20

(2)全部費用=平均each插座30
設插座裝x個
30+20x=30x