Answer:
Step-by-step explanation:
The system of equations given are:
5x - y + z = -6 ------------- i
2x + 7y + 3z = 8 ---------- ii
x + 2z = 6 ----------------- iii
Let us deal with equation i and ii first since they have 3 variables x, y and z;
5x - y + z = -6 x 7
2x + 7y + 3z = 8 x 1
35x - 7y + 7z = -42 ---- iv
2x + 7y + 3z = 8 ---- v
Add equation iv and v;
37x + 10z = -34 ------vi
So, let us solve equation vi and iii:
x + 2z = 6 - ---------- iii x 10
37x + 10z = -34 --- iv x 2
10x + 20z = 60 vi
74x + 20z = -68 vii
Subtract vi - vii;
-64x = 128
x = -2
So; put x = -2 into iii;
x + 2z = 6
-2 + 2z = 6
2z = 6 + 2 = 8
z = 4
Put x = -2 and z = 4 into equation i;
5(-2) - y + 4 = - 6
-10 -y +4 = -6
-6 - y = -6
-y = 0
y = 0
#1
m∠A=180 - 115 - 24 = 41°
By the law of sines:
b/sinB = a/sinA ⇒
b = (a*sinB)/sinA = (21*sin24°)/sin41° = (21*0.4067)/0.656 ≈ 13
c/sinC = a/sinA ⇒
c = (a*sinC)/sinA = (21*sin115°)/sin41° = (21*0.9063)/0.656 ≈ 29
#2
m∠C=180 - 119 - 27 = 34°
By the law of sines:
b/sinB = a/sinA ⇒
b = (a*sinB)/sinA = (13*sin119°)/sin27° = (13*0.8746)/0.454 ≈ 25
c/sinC = a/sinA ⇒
c = (a*sinC)/sinA = (13*sin34°)/sin27° = (13*0.5592)/0.454 ≈ 16
#3
m∠C=180 - 57 - 37 = 86°
By the law of sines:
c/sinC = a/sinA ⇒
c = (a*sinC)/sinA = (11*sin86°)/sin57° = (11*0.9976)/0.8387 ≈ 13.1
Answer:
C Side ZX
Because ZX is a reflection of CD
The correct answer is C. Sample survey
Explanation:
A sample survey is a study method that involves selecting a portion of a population and asking questions to these individuals to know their opinions or insights about a particular situation. Additionally, the answers provided by the selected individuals are used to make conclusions about all the population. This method is the one used in the situation described because the store manager selects only some customers to know about the sales they prefer and would likely use this information to know the preferences of all the customers.
