1.(× + 8) (× -7) 2.(10- ×kuadrat) (× +4) 3.7a + 5a + 4c -5a + c. 4. 7(a + 2b +c) tolong dijawab pakai cara

1, (x +8)(x-7)
= x^2 -7x +8x -56
= x^2 +x -56

2, (10 - x^2)(x +4)
= 10x +40 -x^3 -4x^2
= -x^3 -4x^2 +10x +40

3. 7a +5a +4c -5a +c
= 7a +5a -5a +4c +c
= 7a +5c

4. 7 (a +2b +c)
= 7a +14b + 7c