Sandwich cost $7.70 and the soda costs $2.20.
Answer: x=−10
Step-by-step explanation:
x−3−2(x+6)=−5
x+−3+(−2)(x)+(−2)(6)=−5(Distribute)
x+−3+−2x+−12=−5
(x+−2x)+(−3+−12)=−5(Combine Like Terms)
−x+−15=−5
−x−15=−5
−x−15+15=−5+15
−x=10
Answer:
7.5 L of 10% solution and 22.5 L of 30% solution
Step-by-step explanation:
Volume of 10% solution plus volume of 30% solution = total volume of 25% volume.
x + y = 30
Acid in 10% solution plus acid in 30% solution = total acid in 25% solution.
0.10 x + 0.30 y = 30 × 0.25
0.10 x + 0.30 y = 7.5
Solve the system of equations, using either substitution or elimination. I'll use substitution:
x = 30 − y
0.10 (30 − y) + 0.30 y = 7.5
3 − 0.10 y + 0.30 y = 7.5
0.20 y = 4.5
y = 22.5
x = 30 − y
x = 7.5
Sarah needs 7.5 L of 10% solution and 22.5 L of 30% solution.
Because the parabola opens down and the vertex is at (0, 5), we conclude that the correct option is:
y = -(1/8)*x² + 5.
<h3>
Which is the equation of the parabola?</h3>
The relevant information is that we have the vertex at (0, 5), and that the parabola opens downwards.
Remember that the parabola only opens downwards if the leading coefficient is negative. Then we can discard the two middle options.
Now, because the parabola has the point (0, 5), we know that when we evaluate the parabola in x = 0, we should get y = 5.
Then the constant term must be 5.
So the correct option is the first one:
y = -(1/8)*x² + 5.
If you want to learn more about parabolas:
brainly.com/question/4061870
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