BRAINLIEST!! How many times will the digit '3' appear if we write all whole numbers from 1 to 9999?

4000

Step-by-step explanation:

The amount of times 3 appears from 1-100 is 20 as it appears 10 times as the ones digit and 10 times as the three in the thirties.

Additionally, in the 300s, there are 100 more 3s as each number begins with a three.

So, there are 200+100=300 3s from 1-1000

this means that there are 3000 3s from 1-9999 plus an additional 1000 3s in the 3000s.

In total that is 4000 3s.

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

60

step-by-step explanation:

every triangle measures a total of 120 degrees. you have to find angle c. we know that isosceles triangles angles are equal. 60 degrees plus 60 degrees gives you 120.