Ask question

Ask question

All categories

oksano4ka [1.4K]

3 years ago

9

Given that 2x-7y=30

1 answer:

lidiya [134]3 years ago

4 0

Answer:

y = - $\frac{24}{7}$

Step-by-step explanation:

Substitute x = - 3 into the expression

2x - 7y = 30

2(- 3) - 7y = 30

- 6 - 7y = 30 ( add 6 to both sides )

- 7y = 36 ( divide both sides by - 7 )

y = $\frac{36}{-7}$ = - $\frac{36}{7}$

You might be interested in

What is the square root of 59,005?

gizmo_the_mogwai [7]

242.9 . I worked it out on a piece of paper so it might be right .

7 0

3 years ago

Find the area of a perfect polygon that has 99 sides and each side measures 31 inches

Assoli18 [71]

Answer:95139 units^2

Step-by-step explanation:

(31*31)*99 = 95139

So the answer should be 95139 units ^2

8 0

2 years ago

Water is drained out of tank, shaped as an inverted right circular cone that has a radius of 4cm and a height of 16cm, at the ra

bearhunter [10]

Answer:

$\frac{dh}{dt}=-\frac{1}{2\pi}cm/min$

Step-by-step explanation:

From similar triangles, see diagram in attachment

$\frac{r}{4}=\frac{h}{16}$

We solve for $r$ to obtain,

$r=\frac{h}{4}$

The formula for calculating the volume of a cone is

$V=\frac{1}{3}\pi r^2h$

We substitute the value of $r=\frac{h}{4}$ to obtain,

$V=\frac{1}{3}\pi (\frac{h}{4})^2h$

This implies that,

$V=\frac{1}{48}\pi h^3$

We now differentiate both sides with respect to $t$ to get,

$\frac{dV}{dt}=\frac{\pi}{16}h^2 \frac{dh}{dt}$

We were given that water is drained out of the tank at a rate of $2cm^3/min$

This implies that $\frac{dV}{dt}=-2cm^3/min$ .

Since we want to determine the rate at which the depth of the water is changing at the instance when the water in the tank is 8cm deep, it means $h=8cm$ .

We substitute this values to obtain,

$-2=\frac{\pi}{16}(8)^2 \frac{dh}{dt}$

$\Rightarrow -2=4\pi \frac{dh}{dt}$

$\Rightarrow -1=2\pi \frac{dh}{dt}$

$\frac{dh}{dt}=-\frac{1}{2\pi}$

3 0

4 years ago

Read 2 more answers

If g(X) = 2x-1 , then what is g(3)?

Tanzania [10]

2(3)-1
6-1
5
Good luck :)

7 0

3 years ago

Estimate the quotient using compatible numbers.<br><br> 340 ÷ 5

prisoha [69]

Answer:

70

Step-by-step explanation:

round 340 to 350 because 5 goes into 35,

7 times

then add the 0 to the end.

350 ÷ 5 = 70

4 0

3 years ago