write the standard form of a complex number, giving two examples.
A. a + bi, where a and b are real numbers; examples: 5 + 3i, -2 + 4i
B. a * bi, where a and b are real numbers; examples: 6 * 2i, -1 * 7i
C. a - bi, where a and b are real numbers; examples: 4 - 2i, 1 - 6i
D. bi + a, where a and b are real numbers; examples: 3i + 4, 2i + 1