What is $11.99^2 - 7.02^2$ approximately equal to?

95Correct answerYour answer115Correct answerYour answer135Correct answerYour answer155Correct answerYour answer

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CorrectNot quiteAnswer A

Correct answer: A

$11.99 \approx 12$ and $7.02 \approx 7$ .
$12^2 - 7^2 = 144 - 49 = 95$ . (Or $(12 - 7)(12 + 7) = 5 \times 19 = 95$ .)

Worth noting

Squaring the difference, $(12 - 7)^2 = 25$ , is a common slip; a difference of squares is not the square of a difference. The exact value is about 94.5.

Concept: Estimating a difference of squares
Typical timeTypical: 55 s
Your timeYours: —

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What is 11.992−7.02211.99^2 - 7.02^211.992−7.022 approximately equal to?

Explanation

What is $11.99^2 - 7.02^2$ approximately equal to?