Ask question

Ask question

All categories

3 years ago

8

The value of y varies directly with x, and y=3 when x=9 find y when x = 21

1 answer:

tester [92]3 years ago

3 0

Answer: y = 7

Step-by-step explanation:

Step 1) plug in 3 for y and 9 for x in the direct variation formula, which is y = kx

3 = k(9)

Step 2) Solve for k

3 = k(9) (Divide by 9 on both sides)

3/9 = k (Now simplify 3/9)

1/3 = k. So k = 1/3

*just FYI: “k” is the constant of variation.

Step 3) use the equation y = kx and plug in 1/3 for k

y = 1/3x

Step 4) using the equation y = 1/3x, plug in 21 for x.

y = 1/3(21) (1/3*21 is the same as 21/3)

y = 21/3 (21/3 = 7)

y = 7. So that’s you’re answer! When x=21, y=7 because 7 is 1/3 of 21!

Hope this helps! My best wishes to you as you go through school!

You might be interested in

In the scale used on a blueprint 1/4 inch represent 3 feet on the blueprint what is the length of the room with an excellent of

BigorU [14]

You would do 24 times 3 and get 72 or divide 24 by 1/4=0.25

3 0

2 years ago

I DONT CARE IF YOU LOOK THIS UP JUST DO THE CORRECT ONE ON THE SOURCE AND BEST STARS: https://brainly.com/question/7807259

salantis [7]

Answer:

60% heads

Step-by-step explanation:

7 0

3 years ago

I'LL GIVE YOU BRAINIEST!<br> 1 1/5 · x/3 = 9/10 solve for x

joja [24]

$\huge\text{Hey there!}$

$\huge\textbf{Equation:}$

$\mathbf{1 \dfrac{1}{5} \times \dfrac{x}{3} = \dfrac{9}{10}}$

$\huge\textbf{Solve:}$

$\mathbf{1 \dfrac{1}{5} \times \dfrac{x}{3} = \dfrac{9}{10}}$

$\mathbf{\rightarrow \dfrac{1\times5+1}{5} \times \dfrac{x}{3} = \dfrac{9}{10}}$

$\mathbf{\rightarrow \dfrac{5 + 1}{5} \times \dfrac{x}{3} = \dfrac{9}{10}}$

$\mathbf{\rightarrow \dfrac{6}{5} \times \dfrac{x}{3} = \dfrac{9}{10}}$

$\huge\textbf{Simplify it:}$

$\mathbf{\rightarrow \dfrac{2}{5}x = \dfrac{9}{10}}$

$\huge\textbf{Multiply \boxed{\bf \dfrac{5}{2}} to both sides:}$

$\mathbf{\rightarrow \dfrac{5}{2}\times \dfrac{2}{5}x = \dfrac{5}{2}\times \dfrac{9}{10}}$

$\huge\textbf{Simplify it:}$

$\mathbf{\rightarrow x = \dfrac{5}{2}\times \dfrac{9}{10}}$

$\mathbf{\rightarrow x = \dfrac{5\times9}{2\times10}}$

$\mathbf{\rightarrow x = \dfrac{45}{20}}$

$\mathbf{\rightarrow x = \dfrac{45\div5}{20\div5}}$

$\mathbf{\rightarrow x = \dfrac{9}{4}}$

$\mathbf{x \approx 2 \dfrac{1}{4}}$

$\huge\textbf{Therefore, your answer should be:}$

$\huge\boxed{\mathsf{x = }\frak{2 \dfrac{1}{4}}}\huge\checkmark$

$\huge\text{Good luck on your assignment \& enjoy your day!}$

~ $\frak{Amphitrite1040:)}$

8 0

2 years ago

Read 2 more answers

2 + n = 24 pls help for home work

eimsori [14]

To find the value of n, we need to subtract 2 from 24. 24 - 2 = 22.

So, n = 22.

6 0

3 years ago

What is the value of y so that the equation is true?

polet [3.4K]

Answer:

I guess that You made a mistake and You wanted to solve equations $\sqrt[2]{y}$ . Then the answer is D because There is no number that gives a negative number after the square root

Step-by-step explanation:

7 0

2 years ago