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3 years ago

8

Marian can weed a garden in 3 hrs. Robin can weed the same garden in 4 hrs. If they work together, how long will the weeding tak

e them?

1 answer:

irina1246 [14]3 years ago

8 0

Answer:

The answer would be 12

Step-by-step explanation:

because all u have to do is multiply

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Zach was playing basketball for the Longwood middle school team.he made 60% of his shots.how many total shots did he take,if he

Lostsunrise [7]

60%=0.6. 9=0.6x 9/0.6=15. 15 total shots

6 0

4 years ago

15. Fatima bought a video game that has a

OleMash [197]

Answer:

Step-by-step explanation:

Discount = 15% of 45

$=\frac{15}{100}*45\\\\=\frac{675}{100}=6.75$

= $6.75

Price of the video game = 45 - 6.75 = $38.25

Tax = 7%of 38.25

$=\frac{7}{100}*38.25\\\\=\frac{267.75}{100}=2.6775$

Price paid by Fatima for the video game = 38.25 + 2.68 = $ 40.93

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3 years ago

Jeff writes comic strips for a local newspaper. The number of comic strips he creates is represented by the function f(x) = 3x,

Andrei [34K]

If he does three hours, its 9 strips, for four, its 12, six is 18, seven is 21, and nine is 27

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3 years ago

A tank contains 10 liters of pure water. Saline solution with a variable concentration 5 grams of salt per liter is pumped into

algol [13]

Answer:

dQ(t)/dt = 20 - 2Q(t)/5 , Q(0) = 0

Step-by-step explanation:

The mass flow rate dQ(t)/dt = mass flowing in - mass flowing out

Since 5 g/L of salt is pumped in at a rate of 4 L/min, the mass flow in is thus 5 g/L × 4 L/min = 20 g/min.

Let Q(t) be the mass present at any time, t. The concentration at any time ,t is thus Q(t)/volume = Q(t)/10. Since water drains at a rate of 4 L/min, the mass flow out is thus, Q(t)/10 g/L × 4 L/min = 2Q(t)/5 g/min.

So, dQ(t)/dt = mass flowing in - mass flowing out

dQ(t)/dt = 20 g/min - 2Q(t)/5 g/min

Since the salt just begins to be pumped in, the initial mass of salt in the tank is zero. So Q(0) = 0

So, the initial value problem is thus

dQ(t)/dt = 20 - 2Q(t)/5 , Q(0) = 0

3 0

3 years ago

The first three steps in determining the solution set of the system of equations algebraically are shown in the table. y = −x2 +

lianna [129]

You have a system of equations $\left \{ {{y = -x^2+2x-9} \atop {y =-6x+6}} \right.$ .

1. Substitude right side of second equation into the left side of the first equation: $-6x+6=-x^2+2x-9$ .

2. Solve this equation:
$x^2-2x+9-6x+6=0, \\ x^2-8x+15=0, \\ D=(-8)^2-4\cdot 1\cdot 15=64-60=4, \\ \sqrt{D}=2, \\ x_{1,2}=\dfrac{8\pm 2}{2 } =3,5$ .

3. Find y:
for $x_1=3, y_1=-6\cdot 3+6=-18+6=-12$ ,
for $x_2=5, y_2=-6\cdot 5+6=-30+6=-24$ .

4. The solutions of the system are: (3,-12) and (5,-24).
Answer: Correct choice is A.

7 0

3 years ago

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