Consider,

. Let's say

then the problem reduces to

. (Do you understand this step?)
So then replacing a again with our definition we get,

.
SOLUTION:
Let whole number = x
x + 2x^2 = 21
2x^2 + x - 21 = 0
2x^2 + 7x - 6x - 21 = 0
x ( 2x + 7 ) - 3 ( 2x + 7 ) = 0
( 2x + 7 ) ( x - 3 ) = 0
2x + 7 = 0
2x = - 7
x = - 7 / 2
OR
x - 3 = 0
x = 3
ANSWER:
Therefore, as 3 is a whole number while - 7 / 2 isn't a whole number, the whole number must be 3.
Hope this helps! :)
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Answer:
The answer is 2
Step-by-step explanation:
Let the number be x
10 - (3 + x) = 5
10 - 3 -x = 5
7 - x = 5
x = 7-5
x = 2
Answer:
does anyone know the answer????????
Step-by-step explanation:
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Answer:
17°
Step-by-step explanation:
Let x represent the measure of the angle.
(90 -x) = 5 + 4x . . . . the complement is 5° more than 4 times the angle
85 = 5x . . . . . . . . . . add x-5 to both sides
17 = x . . . . . . . . . . . . divide by 5
The measure of the angle is 17°.