What are the solutions to the equation x2 − 1 = 399?

a. x=20 and x=-20

b. x=200 and x=-200

c. x=400 and x=-400

d. x=398 squared and x=-398 squared

Good evening ,

Answer :

A.

x = ±20

Step-by-step explanation:

x² − 1 = 399 ⇔ x²= 400 ⇌ x² = 20² ⇌ x² − 20² = 0 ⇌ (x-20)(x+20) = 0

⇌ x = 20 or x = -20.

:)

48 / 6 = x

in this case, x will equal the amount of money in each card!

x therefore will be 8.

trent had $8 in each birthday card.

the answer is 1 becuz if it were 1.0 that would rip apart the entire so ya. : )

~potato.

copyright potato 2019.