9514 1404 393
Answer:
2
Step-by-step explanation:
The second step of the solution shows division by 2 on the left. Consequently, it must also show division by 2 on the right.
2 goes in the green box
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A. 2x^2 - 3x + 10 = 2x + 21
2x^2 - 3x - 2x + 10 - 21 = 0
2x^2 - 5x - 11 = 0 (quadratic equation)
2x^2 - 6x - 7 = 2x^2
2x^2 - 2x^2 - 6x - 7 = 0
-6x - 7 = 0 (not a quadratic equation)
5x^2 + 2x - 4 = 2x^2
5x^2 - 2x^2 + 2x - 4 = 0
3x^2 + 2x - 4 (quadratic equation)
5x^3 - 3x + 10 = 2x^2
5x^3 - 2x^2 - 3x + 10 = 0 (not a quadratic equation)
Therefore, options a and c can be solved using the quadratic formula.
Call your unknown number x. The reciprocal would be1/xYou are supposed to add your unknown number to 8 times its reciprocal, orx+8(1/x)This is all supposed to equal 6, so you havex+8/x=6
Solve for x to get your number.
n + 8(1/n) = 6n^2 + 8 = 6nn^2 - 6n + 8 = 0(n - 4)(n - 2) = 0n = 2, 4
So 2 and 4 both are answers in my opinion.
