Question

Bài 17: Viết dưới dạng tích các tổng sau:

1/ ab + ac

2/ ab – ac + ad

3/ ax – bx – cx + dx

4/ a(b + c) – d(b + c)

5/ ac – ad + bc – bd

6/ ax + by + bx + ay

Answer 1

1) ab + ac

= a ( b + c )

2) ab - ac + ad

= a ( b - a + d )

3) ax - bx - cx + dx

= x ( a - b - c + d )

4) a(b + c) - d(b + c)

= ( a - d ) . (b + c )

5) ac - ad + bc - bd

= a ( c - d ) + b ( c - d )

= ( a + b ) . ( c - d )

6) ax + by + bx + ay

= x . ( a + b ) + y . ( a + b )

= ( x + y ) . ( a + b )