3/9=21/k what is the strategy for solving it
1 answer:
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2 + d = 2 - 3(d- 5) - 2
First, cancel 2 on both sides. / Your problem should look like:
Second, expand. / Your problem should look like:
Third, simplify -3d + 15 - 2 to get -3d + 13. / Your problem should look like:
Fourth, add 3d to both sides. / Your problem should look like:
Fifth, add d + 3d to get 4d. / Your problem should look like:
Sixth, divide both sides by 4. / Your problem should look like:
Answer as fraction:
Answer as decimal:
First, cancel 2 on both sides. / Your problem should look like:
Second, expand. / Your problem should look like:
Third, simplify -3d + 15 - 2 to get -3d + 13. / Your problem should look like:
Fourth, add 3d to both sides. / Your problem should look like:
Fifth, add d + 3d to get 4d. / Your problem should look like:
Sixth, divide both sides by 4. / Your problem should look like:
Answer as fraction:
Answer as decimal:
Answer:
66.42°
Step-by-step explanation:
<u>Given:</u>
A(5, 3t+2, 2)
B(1, 3t, 2)
C(1, 4t, 3)
BA • BC = 4
Step 1: Find t.
First we have to find vectors BA and BC. We do that by subtracting the coordinates of the initial point from the coordinates of the terminal point.
In vector BA B is the initial point and A is the terminal point.
BA = OA - OB = (5-1, 3t+2-3t, 2-2) = (4, 2, 0)
BC = OC - OB = (1-1, 4t-3t, 3-2) = (0, t, 1)
Now we can find t because we know that BA • BC = 4
BA • BC = 4
To find dot product we calculate the sum of the produts of the corresponding components.
BA • BC = (4)(0) + (2)(t) + (0)(1)
4 = (4)(0) + (2)(t) + (0)(1)
4 = 0 + 2t + 0
4 = 2t
2 = t
t = 2
Now we know that:
BA = (4, 2, 0)
BC = (0, 2, 1)
Step 2: Find the angle ∠ABC.
Dot product: a • b = |a| |b| cos(angle)
BA • BC = 4
|BA| |BC| cos(angle) = 4
To get magnitudes we square each compoment of the vector and sum them together. Then square root.
Rounded to two decimal places: