who ever solve all these questions i will mark them as the brainliest.
do all sums on a paper.
Hurry up
Answers
Answer:
2) (i) (a-4)(a+4).
By using formula (a-b)(a+b)=a²-b² where a=a & b=4.
(a-4)(a+4)=(a)²-(4)².
=a²-16.
(ii) (2m-5)(2m+5).
By using formula (a-b)(a+b)=a²-b² where a=2m & b=5.
(2m-5)(2m+5)=(2m)²-(5)².
=4m²-25.
(iii) (m+3)(m-3)(m²+9).
(m+3)(m-3)
By using formula (a+b)(a-b)=a²-b² where a=m & b=3.
(m+3)(m-3)=(m)²-(3)².
=m²-9.
(m²+9)(m²-9).
By using formula (a+b)(a-b)=a²-b² where a=m² & b=9.
(m²+9)(m²-9)=(m²)²-(9)².
=m⁴-81.
(iv) (a+bc)(a-bc)(a²+b²c²).
(a+bc)(a-bc).
By using formula (a+b)(a-b)=a²-b² where a=a & b=bc.
(a+bc)(a-bc)=(a)²-(bc)².
=a²-b²c².
(a²+b²c²)(a²-b²c²).
By using formula (a+b)(a-b)=a²-b² where a=a² & b=b²c².
(a²+b²c²)(a²-b²c²)=(a²)²-(b²c²)².
=a⁴-b⁴c⁴.
3) (i) 107×93.
(100+7)(100-7).
(a+b)(a-b)=a²-b² where a=100 & b=7.
(100+7)(100-7)=(100)²-(7)².
=10000-49.
=9951.
(ii) 30.8×29.2.
(30+0.8)(30-0.8).
(a+b)(a-b)=a²-b² where a=30 & b=0.8.
(30+0.8)(30-0.8)=(30)²-(0.8)².
=900-0.64.
=899.36.
Sorry I didn't understand other problems.
I think this is your answer.