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2 years ago

12

To get a final grade of B, a student must have an average mark on five tests that is greater than or equal to 80 and less than 9

0.
If Lisa's grades on the first four tests were 97, 93, 78 and 87, solve for the range of grades x that she could score on the fifth test that would result in her getting a final grade of B.

Give your answer as an inequality.

2 answers:

yulyashka [42]2 years ago

8 0

Answer:

Lisa must get an 88.75 or higher to stay in between 80 and 90.

Step-by-step explanation:

leva [86]2 years ago

3 0

Lisa needs 88.75 for her final grade

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Rachel deposits $100 in a bank account and she gets 8% simple interest on it. Which linear model gives the return on her investm

Mandarinka [93]

The answer would be B because the 100 stays in there and you are adding 8% per year. Hope this helps.

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3 years ago

The 12th term in a sequence with a common difference of-9 is -106. which of the following formulas can be used to represent this

Effectus [21]

Answer:

T12=a-99=106

Step-by-step explanation:

that's the answer

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2 years ago

A trough of water is 20 meters in length and its ends are in the shape of an isosceles triangle whose width is 7 meters and heig

Vaselesa [24]

Answer:

a) Depth changing rate of change is $0.24m/min$ , When the water is 6 meters deep

b) The width of the top of the water is changing at a rate of $0.17m/min$ , When the water is 6 meters deep

Step-by-step explanation:

As we can see in the attachment part II, there are similar triangles, so we have the following relation between them $\frac{3.5}{10} =\frac{a}{h}$ , then $a=0.35h$ .

a) As we have that volume is $V=\frac{1}{2} 2ahL=ahL$ , then $V=(0.35h^{2})L$ , so we can derivate it $\frac{dV}{dt}=2(0.35h)L\frac{dh}{dt}$ due to the chain rule, then we clean this expression for $\frac{dh}{dt}=\frac{1}{0.7hL}\frac{dV}{dt}$ and compute with the knowns $\frac{dh}{dt}=\frac{1}{0.7(6m)(20m)}2m^{3}/min=0.24m/min$ , is the depth changing rate of change when the water is 6 meters deep.

b) As the width of the top is $2a=0.7h$ , we can derivate it and obtain $\frac{da}{dt}=0.7\frac{dh}{dt} =0.7*0.24m/min=0.17m/min$ The width of the top of the water is changing, When the water is 6 meters deep at this rate

8 0

3 years ago

How to solve the system of equation 500y-600x=2800 , 400y-400x=2400 by elimination

tatiyna

Answer:

$x=2$ and $y=8$

Step-by-step explanation:

Given:

Equation 1:

$500y-600x=2800$

Simplifying the above equation by dividing both sides by 100

$\frac{500y-600x}{100}=\frac{2800}{100}$

$\frac{500y}{100}-\frac{600x}{100}=28\\\\5y-6x=28$

Equation 2:

$400y-400x=2400$

Simplifying the above equation by dividing both sides by 400.

$\frac{400y-400x}{400}=\frac{2400}{400}$

$\frac{400y}{400}-\frac{400x}{400}=6\\\\y-x=6$

Now the system of equation is:

(1a) $5y-6x=28$

(2a) $y-x=6$

Solving by elimination

Multiplying equation (2a) with $-5$

$-5(y-x)=-5\times 6$

(2b) $-5y+5x=-30$

Adding equations (1a) and (2b) in order to eliminate $y$

$5y-6x=28$

+ $-5y+5x=-30$

We get $-x=-2$

∴ $x=2$

Plugging $x=2$ in equation (2a).

$y-2=6$

Adding $2$ both sides.

$y-2+2=6+2$

∴ $y=8$

7 0

3 years ago

Pl help I will give you brain lies

antiseptic1488 [7]

Y = 6, x = 5 y = 6, x = 5 y = 6, x = 5

3 0

3 years ago

Read 2 more answers