Find the number of 4-digit numbers that contain a at least three even digits.

2625 namely sum of three options:

All (4) digits are even: 4 possibilities for 1st digit (even but not 0) * 5 for 2nd digit (even) * 5 for 3rd * 5 for 4th = 500

First digit is odd: possibilities are 5 (1st digit odd i.e. in ‘13579’) * 5 (2nd digit even i.e. in ‘02468’) * 5 (3rd digit even) * 5(4th digit even) = 625

Second, third or fourth digit is odd: 4 (1st digit even but not 0) * 5 (even digit) * 5 (even digit) * 5 (odd digit) * 3 (odd digit can be in 2nd, 3rd or 4th position) = 1500

d, x=8

step-by-step explanation:

simplifying

4x + -5 = 2x + 11

reorder the terms:

-5 + 4x = 2x + 11

reorder the terms:

-5 + 4x = 11 + 2x

solving

-5 + 4x = 11 + 2x

solving for variable 'x'.

move all terms containing x to the left, all other terms to the right.

add '-2x' to each side of the equation.

-5 + 4x + -2x = 11 + 2x + -2x

combine like terms: 4x + -2x = 2x

-5 + 2x = 11 + 2x + -2x

combine like terms: 2x + -2x = 0

-5 + 2x = 11 + 0

-5 + 2x = 11

add '5' to each side of the equation.

-5 + 5 + 2x = 11 + 5

combine like terms: -5 + 5 = 0

0 + 2x = 11 + 5

2x = 11 + 5

combine like terms: 11 + 5 = 16

2x = 16

divide each side by '2'.

0.50 , 0.75

step-by-step explanation: