3. Solve the inverse variation problem. y varies inversely with x. If y=7 when t= -4, find y when = 2.

Help me plz<br><br> 2<br> _ Y + 7 = 15<br> 3

julia-pushkina [17]

Answer:

y= 12

Step-by-step explanation:

2/3 y + 7 = 15

Subtract 7 from each side

2/3 y + 7-7 = 15-7

2/3 y = 8

Multiply each side by 3/2 to isolate y

3/2 * 2/3 y = 3/2 * 8

3/2 * 2/3 y = 3 * 4

y = 12

7 0

3 years ago

The quadratic function d = –2x^2 + 15 models a skateboarder’s distance, in feet, from the bottom of a hill x seconds after the s

Ksenya-84 [330]

Answer:

After 1.87 seconds the skateboarder is 8 ft from the bottom of the hill.

Step-by-step explanation:

The quadratic function d = –2*x² + 15 models a skateboarder’s distance, in feet, from the bottom of a hill x seconds after the skateboarder starts moving down the hill.

You want to know after how many seconds the skater is 8 feet from the bottom of the hill. That is, with the distance being 8 feet, you want to calculate the time t. Replacing in the expression d by the value of 8 feet:

8=–2*x² + 15

Solving:

8-15 = -2*x²

-7= -2*x²

(-7)÷(-2)= x²

3.5= x²

√3.5=x

1.87= x

<u><em>After 1.87 seconds the skateboarder is 8 ft from the bottom of the hill.</em></u>

5 0

3 years ago

3(x+2)=2(2x+7) help meeeeeeeeeeeeee

forsale [732]

Use distributive property

3(x + 2) = 2(2x + 7)

(3)(x) + (3)(2) = (2)(2x) + (2)(7)

3x + 6 = 4x + 14 |subtract 6 from both sides

3x = 4x + 8 |subtract 4x from both sides

-x = 8 |change the signs

4 0

3 years ago

Read 2 more answers

The square of the sum of two numbers is 144 and the sum of of their square is 180, find the number... Please I really need the a

mr Goodwill [35]

Answer:

The numbers are either ±13.35 and ±1.35 or ±1.35 and ±13.3

Step-by-step explanation:

Let the two numbers be 'x' and 'y'.

Given:

The squares of the sum of two numbers = 144

The sum of their squares = 180

The sum of the numbers = $x+y$

The square of the sum of numbers = $(x+y)^2$

Square of first number = $x^2$

Square of second number = $y^2$

The sum of their squares = $x^2+y^2$

Now, as per question:

$(x+y)^2=144---(1)\\\\x^2+y^2=180---(2)$

Expanding equation (1) using the formula $(a+b)^2=a^2+b^2+2ab$

This gives,

$(x+y)^2=144\\\\x^2+y^2+2xy=144\\\\\textrm{Plug in the value of }x^2+y^2\textrm{ from equation (2)}\\\\180+2xy=144\\\\2xy=144-180\\\\2xy=-36\\\\xy=-\frac{36}{2}\\\\xy=-18\\\\y=-\frac{18}{x}---(3)$

Plug in the value of 'y' from equation (3) in equation (1). This gives,

$x^2+(-\frac{18}{x})^2=180\\\\x^2+\frac{324}{x^2}=180\\\\x^4+324=180x^2\\\\x^4-180x^2+324=0\\\\\textrm{On solving, we get:}\\\\x^2=178.2\ or\ x^2=1.8\\\\\textrm{Square root both sides, we get:}\\\\x=\pm13.35\ or\ x=\pm1.35$