Adding & Subtracting Complex Numbers

Select all that are true.

• √ -1 is an imaginary number

• There are no real numbers that satisfy the equation x=√-1.

• Because √-1 is imaginary, we cannot do math with it.

• The equation x²=-1 has real solutions.

• √-1 = -1 because -1⋅-1 = -1

Explain why (x+5)² = -10 has no real solutions.

• x² can never equal a negative number because a number times itself will always be postive.

• x² cant be negative

• There is not a number +5 that equals -10.

Find all solutions to each equation, real or imaginary.

x²=4

• 2, -2

• 2

• -2

• 2i, -2i

Find all solutions to each equation, real or imaginary.

x²=-36

• 6,-6

• 6

• -6

• 6i, -6i

Write the expression in the form of a+bi, where a and b are real numbers.

3 ⋅ √-25

• 15

• -15

• 15i

• -15i

Write the expression in the form of a+bi, where a and b are real numbers.

-3i ⋅ 2i

• -6

• 6

• -6i

• 6i

Simplify.

(-6 - 4i) + (1 + 4i) = _______

• -5
• -5+i

• -7-8i

• 5

Simplify.

(9 +21i) + (-7 - 15i)

• 2+6i

• -2-6i

• 16+36i

• -16-36i

Simplify.

(-5 - 5i) - (-3 + 6i)

Simplify.

(-10 + 4i) - (15 - 14i)

• -25+18i

• 25-18i

• 5-10i

• -5+10i