First solve for the other angles.
You know one angle is 15º.
The one across from it is also 15º since it is a vertical angle to the known 15º angle.
Both of those together gets 30º.
The whole thing is 360º, so just subtract 30 from 360 and divide.
360 - 30 = 330
Do the same for the 15x angle.
The one under/across to it is a vertical angle so is also 15xº.
Now you are left with 30xº = 330.
Just divide now.
330 / 30 = 11
x = 11
15x = 165
Checking your work:
15x = 165
15x = 165
15
15
Those are the angles.
Add those numbers together and make sure it adds up to 360º.
165 + 165 + 15 + 15 = 360
So this is correct.
Answer:
76
Step-by-step explanation:
given a quadratic equation in standard form : ax² + bx + c = 0 : a ≠ 0
then the discriminant is Δ = b² - 4ac
given 3x² - 10x = - 2 ( add 2 to both sides )
3x² - 10x + 2 = 0 ← in standard form
with a = 3, b = - 10 and c = 2
b² - 4ac = (- 10)² - (4 × 3 × 2) = 100 - 24 = 76
Answer:
r = - 7, r = - 5
Step-by-step explanation:
Given
r² = - 12r - 35 ( add 12r to both sides )
r² + 12r = - 35
To complete the square
add ( half the coefficient of the r- term )² to both sides
r² + 2(6)r + 36 = - 35 + 36
(r + 6)² = 1 ← take the square root of both sides )
r + 6 = ± 1 ( subtract 6 from both sides )
r = - 6 ± 1, thus
r = - 6 - 1 = - 7 or r = - 6 + 1 = - 5
Answer:
11
Step-by-step explanation:
AB = 3x + 4 and AC which is twice of AB is equal to 11x - 17
2 (3x + 4) = 11x - 17
6x + 8 = 11x - 17
8 + 17 = 11x - 6x
25 = 5x
5 = x
AC = CD = 11x - 17 ➡ 11×5 - 17 = 38
CD = 38 and DE = 49 - 38 = 11
