Question

Find the value using suitable identity
a) 99^2 - 98^2
b) ( 104 )^2
c) 88× 92
d) ( 92 )^2​

Answer 1

Step-by-step explanation:

1)Given that 99²-98²

It is in the form of a²-b²

Here a=99 and b=98

we know that a²-b²=(a+b)(a-b)

=>99²-98²

=>(99+98)(99-98)

=>197(1)

=>197

99²-98²=197

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b)Given that (104)²=(100+4)²

This is in the form of (a+b)²

Here a=100 and b=4

(a+b)²=a²+2ab+b²

=>(100+4)²

=>(100)²+2(100)(4)+4²

=>10000+800+16

=>10816

(104)²=10,816

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c)Given that 88×92

It can be written as (90-2)(90+2)

Here a=90 and b=2

this is in the form of (a+b)(a-b)

=>(a+b)(a-b)=a²-b²

=>(90-2)(90+2)

=(90)²-2²

=>8100-4

=>8096

88×92=8096

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d)Given that (92)²

It can be written as (90+2)²

This is in the form of (a+b)²

Here a=90 and b=2

(a+b)²=a²+2ab+b²

=>(90+2)²

=>(90)²+2(90)(2)+2²

=>8100+360+4

=>8464

(92)²=8464

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Answer 2

Step-by-step explanation:

Given that 99²-98²

It is in the form of a²-b²

Here a=99 and b=98

we know that a²-b²=(a+b)(a-b)

=>99²-98²

=>(99+98)(99-98)

=>197(1)

=>197

99²-98²=197

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b)Given that (104)²=(100+4)²

This is in the form of (a+b)²

Here a=100 and b=4

(a+b)²=a²+2ab+b²

=>(100)