Respuesta :
The answer is spray x: 10, spray y: 5, spray z: 12
a - number of gallons of chemical A
b - number of gallons of chemical B
c - number of gallons of chemical C
x - number of gallons of spray x
y - number of gallons of spray y
z - number of gallons of spray z
CHEMICAL SPRAY X SPRAY Y SPRAY Z
a = 6 = 1/5x + 0y + 1/3z
b = 8 = 2/5x + 0y + 1/3z
c = 13 = 2/5x + y + 1/3z
So:
1/5x + 1/3z = 6
2/5x + 1/3z = 8
2/5x + y + 1/3z = 13
____________
Multiply the first equation by (-1) and add it to the second equation:ž
- 1/5x - 1/3z = - 6
2/5x + 1/3z = 8
____________
1/5x = 2
x = 2 * 5 = 10
From here:
1/5x + 1/3z = 6
x = 10
___________
1/5 * 10 + 1/3z = 6
2 + 1/3z = 6
1/3z = 4
z = 4 * 3 = 12
1/5x + y + 1/3z = 13
x = 10
z = 12
______
2/5 * 10 + y + 1/3 * 12 = 13
4 + y + 4 = 13
8 + y = 13
y = 13 - 8 = 5
a - number of gallons of chemical A
b - number of gallons of chemical B
c - number of gallons of chemical C
x - number of gallons of spray x
y - number of gallons of spray y
z - number of gallons of spray z
CHEMICAL SPRAY X SPRAY Y SPRAY Z
a = 6 = 1/5x + 0y + 1/3z
b = 8 = 2/5x + 0y + 1/3z
c = 13 = 2/5x + y + 1/3z
So:
1/5x + 1/3z = 6
2/5x + 1/3z = 8
2/5x + y + 1/3z = 13
____________
Multiply the first equation by (-1) and add it to the second equation:ž
- 1/5x - 1/3z = - 6
2/5x + 1/3z = 8
____________
1/5x = 2
x = 2 * 5 = 10
From here:
1/5x + 1/3z = 6
x = 10
___________
1/5 * 10 + 1/3z = 6
2 + 1/3z = 6
1/3z = 4
z = 4 * 3 = 12
1/5x + y + 1/3z = 13
x = 10
z = 12
______
2/5 * 10 + y + 1/3 * 12 = 13
4 + y + 4 = 13
8 + y = 13
y = 13 - 8 = 5
Answer:
10 gallons of chemical x, 5 gallons of chemical y, and 12 gallons of chemical z
Step-by-step explanation:
Set up the system of equations:
1/5 x + 0 y + 1/3 z = 6
2/5 x + 0 y + 1/3 z = 8
2/5 x + 1 y + 1/3 z = 13
Arrange them as matrices:
[tex]\left[\begin{array}{ccc}1/5&0&1/3\\2/5&0&1/3\\2/5&1&1/3\end{array}\right][/tex] × [tex]\left[\begin{array}{ccc}x\\y\\z\end{array}\right][/tex] = [tex]\left[\begin{array}{ccc}6\\8\\13\\\end{array}\right][/tex]
Multiply the inverse of the 3x3 matrix by the "result" matrix:
[tex]\left[\begin{array}{ccc}-5&5&0\\0&-1&1\\6&-3&0\end{array}\right][/tex]×[tex]\left[\begin{array}{ccc}6\\8\\13\\\end{array}\right][/tex]= [tex]\left[\begin{array}{ccc}10\\5\\12\\\end{array}\right][/tex]
This tells you that you need 10 gallons of chemical x, 5 gallons of chemical y, and 12 gallons of chemical z to make the mixture.