Question

Melody picks a number. She triples the number, squares the result, divides the square by 2, subtracts 30 from the quotient, and gets 42. What are the possible numbers that Melody could have picked?

Answer 1

The possible numbers that Melody could have picked are -4 and 4.

The operation that prevents us from knowing with 100% certainty the number Melody had picked is multiplication which is implied by the phrase "double the number".

Given, Let x be the number Melody had chosen.

Thus, tripling the number will give 3x, and

squaring this will result to (3x)² which is equals to 9x².

Dividing the square of the number by 2 and subtracting 30 from its quotient will give 42:

9x²/2 ₋ 30 = 42

9x²/2 = 42 ₊ 30

9x²/2 = 72

9x² = 72 × 2

9x² = 144

x² = 144/9

x² = 16

x = ±√16

x = ±4

x = ₊4 or x = 4

hence melody could have picked ₊4 or ₋4 numbers.

Learn more about Equations here:

brainly.com/question/22688504

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