What two variables are used most often in 2-variable equations?

Solve this multistep equation: 3x+20 = x + 30

agasfer [191]

Answer:

x=5

Step-by-step explanation:

Subtract 20

from both sides of the equation

2

Simplify

Subtract the numbers

3

Subtract x

from both sides of the equation

7 0

3 years ago

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if 28 students out of 35 in our class enjoy using electronics in their spare time, how many would you expect out of the 300stude

max2010maxim [7]

Answer:

240 students

Step-by-step explanation:

28/35=x/300

cross multiply to get 35x=300*28

divide both sides by 35 to get 240

4 0

3 years ago

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What is the common ratio Between successive terms in the sequence? 1.5,1.2,0.96,0.768

lidiya [134]

Answer:

0.8

Step-by-step explanation:

0.768/0.96= 0.8

0.96/1.2 =0.8

4 0

4 years ago

The surface area of a sphere is decreasing at the constant rate of 3*pi sq. cm/sec . ? At what rate is the volume of the sphere

Eva8 [605]

Surface area of a sphere: $A=4\pi r^2$
Volume of a sphere: $V=\dfrac43\pi r^3$

Differentiate both with respect to an arbitrary variable for time:
$\displaystyle\frac{\mathrm dA}{\mathrm dt}=8\pi r\frac{\mathrm dr}{\mathrm dt}$
$\displaystyle\frac{\mathrm dV}{\mathrm dt}=4\pi r^2\frac{\mathrm dr}{\mathrm dt}$

You're given that $\dfrac{\mathrm dA}{\mathrm dt}=-3\pi$ when $r=2$ , so you can use this in the first equation to solve for $\dfrac{\mathrm dr}{\mathrm dt}$ .

$-3\pi=8\pi \times2\dfrac{\mathrm dr}{\mathrm dt}\implies\dfrac{\mathrm dr}{\mathrm dt}=-\dfrac3{16}$

Now use this to find $\dfrac{\mathrm dV}{\mathrm dt}$ .

$\displaystyle\frac{\mathrm dV}{\mathrm dt}=4\pi \times2^2\times\left(-\dfrac3{16}\right)=-3\pi$

3 0

4 years ago

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0.8x = 12. Solve for X. PLEASEEE HELPPP!!

kenny6666 [7]

Answer:

x-15

Step-by-step explanation:

7 0

3 years ago

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