Est ce que vous pouvez m’aider… Merci

Réponse:

[tex]\huge\fbox\red{Question:-}[/tex]

evaluate using the given identity.

[tex] {a}^{2} - {b}^{2} [/tex]

solve the following

(1)[tex]207 \times 303[/tex]

(2)[tex]78 \times 82[/tex]

(3)[tex]102 \times 98[/tex]

[tex]\huge\fbox\green{Solution:-}[/tex]

[tex](1) \: 207 ×303 \\ we \: know \: that: \\ {a}^{2} - {b}^{2} = (a + b)(a - b) \\ → (300 + 3)(300 - 3)\\ → {300}^{2} - {3}^{2} \\ → 90000 - 9 \\ = 9991 \\ \\ [/tex]

[tex](2)\:78×82 \\we \: know \: that: \\ {a}^{2} - {b}^{2} = (a + b)(a - b)\\ →(80+2)(80-2)\\{80}^{2} - {2}^{2}\\ → 6400 - 4 \\ = 6399 \\ \\ [/tex]

[tex](3) \: 102 \times 98 \\ we \: know \: that: \\ {a}^{2} - {b}^{2} = (a + b)(a - b) \\ →(100 + 2)(100 - 2) \\ → {100}^{2} - {2}^{2} \\ →10000 - 4 \\ =9996[/tex]

[tex]\huge\fbox\pink{hope\:it\:helps\:you}[/tex]