數學問題(英文)，需要連詳細答案 Thanks?

2019-08-13 11:02 pm

回答 (1)

2019-08-14 2:56 am

2a + b = 17.5····①
a + b + c = 16···②
2a + c = 16.5····③

① - 2(③ - ②)

a - b = 0.5

2a - 2b = 1

3b = 16.5

b = $ 5.5 #

👍 1 👎 0