Answer:
(b) the unknown angle is 80°
Step-by-step explanation:
The unkown angle is:
[2(x-10)]°
Substituting "x" by 50 (part a)
[2(50-10)]°=[2(40)]°=80°
Answer:
Option D. minimum value at −38
Step-by-step explanation:
we have

Let

Complete the square




------> equation of a vertical parabola in vertex form
The vertex is the point 
The parabola open upward-----> the vertex is a minimum
therefore
minimum value at −38
Answer:
s = -7.8
Step-by-step explanation:
from the question 12=10(s+4)+50
<u>first step</u>
open the bracket and evaluate for the value of s
12=10(s+4)+50
12 = 10s + 40 + 50
12 = 10s + 90
collect or combine the like terms
12-90 = 10s
-78 = 10s
divide both side by 10
-78/10 = 10s/10
-7.8 = s
therefor s = -7.8
<span>Simplifying
3a2 + -2a + -1 = 0
Reorder the terms:
-1 + -2a + 3a2 = 0
Solving
-1 + -2a + 3a2 = 0
Solving for variable 'a'.
Factor a trinomial.
(-1 + -3a)(1 + -1a) = 0
Subproblem 1Set the factor '(-1 + -3a)' equal to zero and attempt to solve:
Simplifying
-1 + -3a = 0
Solving
-1 + -3a = 0
Move all terms containing a to the left, all other terms to the right.
Add '1' to each side of the equation.
-1 + 1 + -3a = 0 + 1
Combine like terms: -1 + 1 = 0
0 + -3a = 0 + 1
-3a = 0 + 1
Combine like terms: 0 + 1 = 1
-3a = 1
Divide each side by '-3'.
a = -0.3333333333
Simplifying
a = -0.3333333333
Subproblem 2Set the factor '(1 + -1a)' equal to zero and attempt to solve:
Simplifying
1 + -1a = 0
Solving
1 + -1a = 0
Move all terms containing a to the left, all other terms to the right.
Add '-1' to each side of the equation.
1 + -1 + -1a = 0 + -1
Combine like terms: 1 + -1 = 0
0 + -1a = 0 + -1
-1a = 0 + -1
Combine like terms: 0 + -1 = -1
-1a = -1
Divide each side by '-1'.
a = 1
Simplifying
a = 1Solutiona = {-0.3333333333, 1}</span>