2題中3數學題 help!!

1. 10ap +15aq -10bp - 15bq
= 10ap -10bp +15aq -15bq
排位
= 10p(a - b) + 15q(a - b)
左邊抽左10p, 右邊抽左15q
= (a - b)(10p + 15q)
兩邊都有(a-b),抽埋佢出來,不過未完
= 5(a - b)(2p + 3q)
仲有5可以抽到出來,依個就係最後答案~

2. (x^2+16x+64)-(y+2)^2
= (x^2+16x+8^2) -(y+2)^2
先睇前面個段 : a^2+2ab+b^2 = (a+b)^2
= (x+8)^2-(y+2)^2
a^2-b^2 = (a+b)(a-b) a=(x+8)^2 b=(y+2)^2
= ((x+8)+(y+2))((x+8)-(y+2))
解番d括號
= (x+8+y+2)(x+8-y-2)
計埋d加減數
= (x+y+10)(x-y-6)

應該就係咁~我都寫到有d亂
希望幫到你啦^.^

1. 10p(a-b)+10q(a-b) =10(p+q)+(a-b)