The answer to the question is point slope form
5x + y = 9....multiply by 7
10x - 7y = -18
----------------
35x + 7y = 63 (result of multiplying by 7)
10x - 7y = -18
----------------add
45x = 45
x = 45/45
x = 1
5x + y = 9
5(1) + y = 9
5 + y = 9
y = 9 - 5
y = 4
solution is : (1,4)
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-4x + 9y = 9
x - 3y = -6 ....multiply by 4
----------------
-4x + 9y = 9
4x - 12y = -24 (result of multiplying by 4)
---------------add
- 3y = - 15
y = -15/-3
y = 5
x - 3y = -6
x - 3(5) = -6
x - 15 = -6
x = -6 + 15
x = 9
solution is : (9,5)
Answer:
78 pounds
Step-by-step explanation:
Let's say Yolanda makes a pounds of Type A coffee and b pounds of Type B coffee. Since the total number of pounds is 130, we can write the equation:
a + b = 130
We know the cost of Type A coffee is $5.20/lb and the cost of Type B coffee is $4.05/lb, so since the total cost is $586.30, we can write:
5.20a + 4.05b = 586.30
We can now solve the system of equations:
a + b = 130
5.20a + 4.05b = 586.30
Manipulate the first equation by subtracting b from both sides:
a + b = 130
a = 130 - b
Substitute 130 - b for a in the second equation:
5.20a + 4.05b = 586.30
5.20 * (130 - b) + 4.05b = 586.30
676 - 5.20b + 4.05b = 586.30
Move the terms with b to one side:
1.15b = 89.70
b = 78
Thus, Yolanda used 78 pounds of Type B coffee.
<em>~ an aesthetics lover</em>
