# 英文數學解題

Fred works in a department store. She gets paid an hourly retainer and

fixed percentage of commission on the sales she makes. Last week Fre

d earned $450 gross income agter working 20 hours and selling $3500 worth of merchandise. This week she sold $4000 worth of merchandise and worked for 15 hours which earned her $475. What is Fred's retainer and what percentage of commission is she earning?

我要的不是翻譯 我要的是解答還有算式過程

### 2 Answers

- 寶寶Lv 51 decade agoFavorite Answer
Fred works in a department store. She gets paid an hourly retainer and

fixed percentage of commission on the sales she makes. Last week Fre

d earned $450 gross income agter working 20 hours and selling $3500 worth of merchandise. This week she sold $4000 worth of merchandise and worked for 15 hours which earned her $475. What is Fred's retainer and what percentage of commission is she earning?

他這題的意思是說

Fred 的薪水除了時薪之外 還有一個固定percentage的業績獎金

那我們把percentage設成 X %

薪水設為 $ Y / hour

那我們式子就能列為

450 = 20 Y + 3500 * X %

475 = 15 Y + 4000 * X %

↓

把兩個式子簡化一下

90 = 4 Y + 700 * X %

95 = 3 Y + 800 * X %

↓

將第一式 * -3 第二式 * 4

-270 = -12 Y - 2100 * X %

380 = 12 Y + 3200 * X %

↓

將兩式相加

110 = 1100 * X %

X % = 110 / 1100 = 0.10 = 10 %

↓

將10 % 帶回去

380 = 12 Y + 3200 * 10 %

12Y = 380 – 3200 * 10 / 100 = 60

Y = $ 5 / hour

↓

X = 10%

Y = $ 5 / hour

Source(s): me - worst emotionLv 41 decade ago
X= an hour working retain

Y= percentage of comission

450=20X + 3500Y

475=15X + 4000Y

25= -5X+500Y

-5X=500Y-25

X=100Y-5

450=20(100Y-5)+3500Y

450=2000Y-100+3500Y

550=5500Y

Y=0.1=10%

450=20X + 3500(0.1)

450-350=20X

100=20X

X=5

What is Fred's retainer? 5 dollars per hour retain

what percentage of commission is she earning? 10% of commission