Rule needed: i^2 = -1
Standard form a + bi
(3 + 2i)(7 - 5i) FOIL
3 * 7 = 21
3 * - 5i = - 15i
2i * 7 = 14i
2i * -5i = - 10i^2 = - 10 * -1 = 10
Putting it all back together.
31 - i
Answer:
x = 27
Step-by-step explanation:
∠ CAD and ∠ EDF are corresponding angles and are congruent, so
∠ CAD = 2x
The sum of the 3 angles in Δ ABD = 180°
sum the angles and equate to 180
72 + 2x + 2x = 180
72 + 4x = 180 ( subtract 72 from both sides )
4x = 108 ( divide both sides by 4 )
x = 27
2/3 is basically 0.6666666667 which is the same as 66% so any percentage bigger than 66% such as 75% (0.75) which is 3/4 (as a fraction) is bigger than 2/3
You have to explain how you knew to use 55 and 120, not another option.
Hope it helped! :)