Wendy received a bill for $25 from a magazine club. She paid the magazine club $25. This can be expressed by the following equation.
25+ (-25) = 0
Which mathematical property justifies that the balance in her account is $0?
A. additive inverse
B. multiplicative inverse
C. additive property of zero
D. distributive property

The mathematical property 'additive inverse' justifies that the balance in her account is $0.

Step-by-step explanation:

We know that the additive inverse is what we add to a number to obtain zero.

In other words, the sum of a number and its opposite is zero.

so

When we write the equation

25+ (-25) = 0

It means the mathematical property 'additive inverse' justifies that the balance in her account is $0.

Because the additive inverse of +25 is -25, and the sum of 25+ (-25) is zero.

Therefore, the mathematical property 'additive inverse' justifies that the balance in her account is $0.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15