Answer: C. 42
Step-by-step explanation:
(3x + 3) is the same angle as 129.
So, you have to equal them to each other.
3x + 3 = 129
Now you solve.
Subtract 3 from each sides.
3x = 126
Divide 3 from each side.
x=42
10x^4y^4+2x^6-15y^6-3x^2y^2
I think it’s the last one
Let x represent the gallons of water that is 10% salt.
Let y represent the gallons of water that is 25% salt.
Now, write the system of equations:
x + y = 10
.10x +.25y = 0.20 • 10
1) To make the system easier to solve, multiply all the terms in .10x +.25y = 0.20(10) by 100 to make them integers.
10x + 25y = 20 • 10
10x + 25y = 200
2) Solve for x.
x + y = 10
x = 10 - y
3) Substitute x with 10 - y in the other equation.
10(10 - y) + 25y = 200
100 - 10y + 25y = 200
Combine like terms.
100 + 15y = 200
Subtract 100 from both sides.
15y = 100
y = 20/3 or 6 2/3
4) Now that we have the numerical value of y, solve for the value of x by substituting once more.
a) x + y = 10
x + 20/3 = 10 or x + 6 2/3 = 10 (either equation is fine)
x = 10/3 or x = 3 1/3
The manager should combine 3 1/3 (3.33) gallons of 10% salt water and 6 2/3 (6.67) gallons of 25% salt water.
5) Always check the answers to make sure.
a) x + y = 10
3 1/3 + 6 2/3 = 10
9 3/3 = 10
10 = 10
b) .10x +.25y = 0.20 • 10
.10(3 1/3) +.25(6 2/3) = 0.20 • 10
1/3 + 5/3 = 2
6/3 = 2
2 = 2
<span>1.25 = 0.75x + 50
0.75x = 1.25 - 50
0.75x = -48.75
x = -48.75 / 0.75
x = 65</span>
