3.) 4+(15+26)=(4+15)+26

Step-by-step explanation:

Use pemdas:

(15+26)=41

(4+15)=19

Rewrite the question: 4+41+19+26= 90

a complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is a solution of the equation x2 = −1. because no real number satisfies this equation, i is called an imaginary number. has no real solution, since the square of a real number cannot be negative.