Simple equestion

👨🏻‍🏫 學術台數學

肥胖人

2006-11-19 7:48 pm

Please find the unknown.You shouls show all the steps.

(a+20)+(a+10)+50+(5a-5)=180

回答 (10)

用戶180021

2006-11-19 7:52 pm

✔ 最佳答案

(a+20)+(a+10)+50+(5a-5)=180

a+20+a+10+50+5a-5=180

(a+a+5a)+20+10+50-5=180

7a+75=180

7a=180-75

7a=105

a=15

參考: me

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cass

2006-11-19 8:38 pm

a+20+a+10+50+5a-5=180
7a+75=180
7a=115
a=15

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Ka Chuk

2006-11-19 8:27 pm

a+20+a+10+50+5a-5=180
a+a+5a+20+10+50-5=180
7a+75=180
7a=105
a=15

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用戶19809

2006-11-19 8:17 pm

(a+20)+(a+10)+50+(5a-5)=180
a+20+a+10+50+5a-5=180 (The distributive law of multiplication)
a+a+5a+20+10+50-5=180 (Collecting the like terms)
7a+75=180 (Simplification)
7a=105
a=15

Check:
L.H.S.=(a+20)+(a+10)+50+(5a-5)
=(15+20)+(15+10)+50+[5(15)-5]
=35+25+50+70
=180
=R.H.S.
Therefore a=15 satisfies the equation.

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