Đáp án+Giải thích các bước giải:

 $\color{#a8b0b4}{⸻}\color{#91999d}{⸻}\color{#7a8286}{⸸}\color{#636b6f}{⛧}
\color{#4c5356}{𝕯}\color{#434a4d}{ψ}\color{#3b4244}{ภ}\color{#32393b}{ค}
\color{#2a3133}{๓}\color{#21282a}{๏}\color{#1a2123}{ภ}\color{#141a1c}{ร}
\color{#0f1516}{ฬ}\color{#0a1011}{๏}\color{#05090a}{ɭ}\color{#020406}{๔}
\color{#05090a}{⛧}\color{#0a1011}{⸸}\color{#141a1c}{⸻}\color{#1a2123}{⸻}$

 `1)x^{2}-y^{2}-3x+3y`

`=(x^{2}-y^{2})-(3x-3y)`

`=(x-y).(x+y)-3.(x-y)`

`=(x-y).(x+y-3)`

`2)(b-a)^{2}+(a-b).(3a-2b)-a^{2}+b^{2}`

`=(a-b)^{2}+(a-b).(3a-2b)-(a^{2}-b^{2})`

`=(a-b).(a-b+3a-2b)-(a-b).(a+b)`

`=(a-b).(4a-3b-a-b)`

`=(a-b).(3a-4b)`