After earning interest, the balance of an account is $420. the new balance is 7/6 of the original balance. write an equation that can be used to find the original balance b of the account.

The current balance is $420.

The current balance is 7/6 of the original balance, b

equation to use to find b

Equate the two descriptions of the current balance.

... $420 = (7/6)b . . . . . equation to use to find b

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

asdsad

step-by-step explanation: