Which set has the property of closure under the operation of addition?
(1) {0,1,2}
(2) {x|x is an odd integer}
(3) {0, 1, 2, 3, ..., 10}
(4) {x|x is an even integer}

it's (4)

The set of integers is closed under the operation of addition because the sum of any two integers is always another integer and is therefore in the set of integers.

in (4) set of all even numbers {2, 4, 6, 8, 10,, inf.}

2+4=6 (element of the set)

4+6=10 (element of the set)

so the answer is (4) {x|x is an even integer}

Step-by-step explanation:

brainliest plz

a) justify

step-by-step explanation:

justifying is just part of everyday life. justify kind of means proof so i think the answer is a) justify.

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47