Question

Which of these numbers is four less than a square number?
A 3
B 20
C 37
D 45​

Answer 1

45

Explanation:

basically what we are trying to find is x + 4= square

for you to understand this better, take eg 5.

5 + 4 = 9

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four less than the square number( 9 is the square of 3)

we took the square of 3 and subtracted 4 from it making the result 4 less

12 + 4 = 16

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four less than the square number( 16 is the square of 4)

we took the square of 4 and subtracted 4 from it making the result 4 less

understanding that,

a)3

3 + 4 = 7

there is no square root of 7 X

b)20

20 + 4 = 24

there is no square root of 24 X

c)37

37 + 4 = 41

there is no square root of 41 X

d) 45

45 + 4 = 49

the square root of 49 = 7

answer=49

Answer 2

D

Explanation:

You first add 4 to all of the numbers giving you 7, 24, 41, and 49. Only choice D is a perfect square. for reference, 7*7=49