I need help with these question please help me!!

Solve the equation:<br> <img src="https://tex.z-dn.net/?f=%5Cfrac%7B21%20-%204x%7D%7B9%7D" id="TexFormula1" title="\frac{21 - 4x

schepotkina [342]

Answer:

$x = -\frac{12}{5}$

Step-by-step explanation:

To solve the equation, isolate x. Whatever you do to isolate x one on side, you must do to the other.

1) Multiply both sides by 9 to get rid of the fractions.

$\frac{21-4x}{9} +\frac{8x+15}{3} = 2 \\21-4x + 3(8x + 15) =18 \\$

2) Distribute the 3 to 8x and 15. Then, combine like terms.

$21-4x + 24x + 45 = 18 \\66 + 20x = 18$

3) Move the 66 to the other side, subtracting 18 by 66, then divide each side by 20 to finally isolate x.

$20x = -48\\x = -\frac{48}{20} \\x =- \frac{12}{5}$

Thus, $x = -\frac{12}{5}$ .

3 0

3 years ago

Which situation is most likely to have a constant rate of change?

Vera_Pavlovna [14]

Answer:

b

Step-by-step explanation:

each brick is the exact same size.

(Also can I please have brianliest? I need it to level up!!!)

3 0

3 years ago

Simplify<br> 25 × t⁻⁴ /5⁻³×10⁻²×t⁻⁸<br> plsssssssssssssss help

Anettt [7]

Answer:

Step-by-step explanation:

$\frac{25*t^-^4}{5^-^3*10^-^2*t^-^8}$

Could you confirm to me that this is in fact the problem? Do not report. I will edit this answer once you answer my question.

7 0

3 years ago

A 2000 gallon fish aquarium can be filled by water flowing at a constant rate in 10 hours. When a decorativve rock is placed in

Elza [17]

Answer:

The volume of the rock is 13.368 cubic feet.

Step-by-step explanation:

The volume of the rock ( $V_{r}$ ), measured in gallons, is equal to the volume of the fish aquarium without the decorative rock ( $V'$ ) minus the volume of the fish aquarium with the decorative rock ( $V''$ ), both measured in gallons.

Since the water flow is at constant rate, the volume of the rock is expressed by the following equation:

$V_{r} = V' - V''$

$V_{r} = \dot V \cdot (\Delta t_{1}-\Delta t_{2})$ (1)

Where:

$\dot V$ - Flow rate, measured in gallons per hour.

$\Delta t_{1}$ - Filling time of the fish aquarium without the decorative rock, measured in hours.

$\Delta t_{2}$ - Filling time of the fish aquarium with the decorative rock, measured in hours.

And the flow rate is:

$\dot V = \frac{2000\,gal}{10\,h}$

$\dot V = 200\,\frac{gal}{h}$

The flow rate is 200 gallons per hour.

If we know that $\dot V = 200\,\frac{gal}{h}$ , $\Delta t_{1} = 10\,h$ and $\Delta t_{2} = 9.5\,h$ , then the volume of the rock is:

$V_{r} = \left(200\,\frac{gal}{h}\right)\cdot (10\,h-9.5\,h)$

$V_{r} = 100\,gal$

$V_{r} = 13.368\,ft^{3}$

The volume of the rock is 13.368 cubic feet.

8 0

3 years ago

A spinner is divided into 12 equal sections numbered 1-12. What is the probability of landing on a section with a number that is

denis-greek [22]

Answer:

4/12

Step-by-step explanation:

There is a 1 in 12 chance of any number being spun on the wheel. Because there are 4 numbers less than 5, there is a 4 in 12 chance of one of those numbers being spun.

6 0

3 years ago