which expression represents purely real numbers and which expression represents non-real complex number?

Incomplete question. However, I provided some explanation about non-real complex numbers.

Explanation:

In Mathematics, the term complex numbers (non-real complex numbers) in simple terms refers to numbers that containing an imaginary addition to it.

For example, the numbers 3i, 3 + 5i, 3i/4 are non-real numbers because of the addition of an imaginary part which is denoted by 'i'.

While real numbers, on the other hand, are numbers that do not include an imaginary part; they stand on their own, such as whole numbers 0, 1, 2, 3, etc, rational numbers like 3/4, etc.

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58