Ihave the same value as a group of 2 dimes and 1 nickel. what coin am i?

The answer would simply be a quarter. A dime is equal to 10 cents, two dimes would be 20 cents. A nickel is 5 cents. When you add them together, it equals to 25 cents, which is equivalent to a quarter.

You are a  quarter

Step-by-step explanation:

Dimes are €10 10x2=20 and nickels are€5 20 +5=25 so €25

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