simplify (-1-3i)*(-1+i)
Let's simplify: (-1 -3i)×(-1 + i)
ⓘ Expand by multiplying each term inside the parentheses: (-1 -3i)×(-1 + i) = -1×(-1) -1×i -3i×(-1) -3×i×i
-1×(-1) -1×i -3i×(-1) -3×i×i
ⓘ Multiplications are done before additions and subtractions. Two minus signs cancel out, the product of two negative numbers is positive: -1×(-1) = 1, -3×(-1) = 3■Multiplying by 1 changes nothing: 1×i = i■Multiplying powers with the same base adds the exponents: i×i = i2
1 -i + 3i -3i2
ⓘ Like terms are grouped by adding their coefficients: -i + 3i = 2i■Multiplying by -1 gives the opposite: -3×(-1) = 3■i^2 = -1, so the powers of i reduce to 1, i, -1 or -i: i2 = -1
1 + 2i + 3
ⓘ Start from 1 and move forward 3 on the number line: 1 + 3 = 4
▶Simplified form:   4 + 2i