The simplified expression of (7 + 9i)(8 - 10i) is 146 + 2i
<h3>How to simplify the expression?</h3>
The expression is given as:
(7 + 9i)(8 - 10i)
Expand the bracket
7 * 8 + 9i * 8 -7 * 10i - 9i * 10i
Evaluate the products
56 + 72i -70i - 90(i²)
Evaluate the difference
56 + 2i - 90(i²)
In complex numbers;
i² = -1
So, we have:
56 + 2i - 90(-1)
Evaluate
56 + 2i + 90
Add the like terms
146 + 2i
Hence, the simplified expression of (7 + 9i)(8 - 10i) is 146 + 2i
Read more about complex numbers at:
brainly.com/question/10662770
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Answer:
BC = 6.8
Step-by-step explanation:
The distance from A to B, then from B to C, is the same distance as from A to C.
Thus,
AB + BC = AC
AB = 8x + 8
BC = 4x + 2
AC = 22
AB + BC = AC
(8x + 8) + (4x + 2) = 22
Expanding the parenthesis:
8x + 8 + 4x + 2 = 22
8x + 4x + 8 + 2 = 22
12x + 12 = 22
Subtracting 12 from both sides:
12x = 10
Dividing both sides by 12:
x = 10/12 = 1.2
x = 1.2
We're looking for BC. As we know,
BC = 4x + 2
Let's now put in x = 1.2 into this equation:
BC = 4x + 2
BC = 4 * 1.2 + 2
Since 4 * 1.2 is 4.8:
BC = 4.8 + 2
BC = 6.8
Answer: BC = 6.8
8 x 7 x 10 x 6 = 3360 ft . I believe this should be the answer.
