7.化簡
【Jiunndar Yeh】評論
x+2/5 - 2x+1/3 + 1= 3 * (x + 2)/5 * 3 - 5 * (2x + 1)/3 * 5 + 1= (3x + 6 - 10x - 5)/15 + 1= (-7x + 1)/15 + 15/15= (-7x + 16)/15 ...選項(B)正確