The mean of the scores obtained by a class of students on a physics test is 42. the standard deviation is 8%. students have to score at least 50to pass the test.assuming that the data is normally distributed, approximately (% of the students passed the test.resetnext

  A. (4x +3)²

  B. (2x -7y)(2x +7y)

Step-by-step explanation:

An exponent is conventionally indicated by a caret (^). Only the first number or letter after the caret is the exponent, unless you put parentheses.

A. The form of a perfect square trinomial is ...

  (a +b)^2 = a^2 +2ab +b^2

The factors are easily found as the square roots of the first and last terms.

  16x^2 +24x +9 = (√(16x^2) +√9)^2 = (4x +3)^2

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B. The factorization of the difference of squares is another form you can memorize.

  a^2 - b^2 = (a -b)(a +b)

Here, you have ...

  a = √(4x^2) = 2x

  b = √(49y^2) = 7y

so, the factorization is ...

  (2x -7y)(2x +7y)