There are two ways to work this out: normal variables or using "imaginary" numbers.
Normal variables:
![(7+2i)(3-i)\\(7*3)+[7*(-i)]+(3*2i)+[2i*(-i)]\\21-7i+6i-2i^{2}\\\\21-i-2i^{2}](https://tex.z-dn.net/?f=%20%287%2B2i%29%283-i%29%5C%5C%287%2A3%29%2B%5B7%2A%28-i%29%5D%2B%283%2A2i%29%2B%5B2i%2A%28-i%29%5D%5C%5C21-7i%2B6i-2i%5E%7B2%7D%5C%5C%5C%5C21-i-2i%5E%7B2%7D)
Imaginary numbers:
Using the result from earlier:
![21-i-2i^{2}](https://tex.z-dn.net/?f=21-i-2i%5E%7B2%7D)
Now since
![i = \sqrt{-1}](https://tex.z-dn.net/?f=%20i%20%3D%20%5Csqrt%7B-1%7D)
, then the expression becomes:
4×10-9×10=-50
-5×10-5×20-36×10-36×20=-870
<span>△PQR is similar to △STU
</span>m∠R = m∠U = 96°
m∠Q = m∠T = 6
m∠P = 180 - ( 96 + 6)
m∠P = 180 - 102
m∠P = 78
answer
m∠P = 78
Step-by-step explanation:
sec⁴B - sec²B = sec²B(sec²B - 1)
= (1 + tan²B)(tan²B)
= tan⁴B + tan²B
= Right-hand side (Proven)
Answer:
45 degrees
Step-by-step explanation:
because 2 and 5 are vertical angles they are therefore congruent by definition, 5 is half of one and one is a right angle so measure angle 2 = 45 degrees