How do you solve 7p^2+16=2151?

2 Answers
Zero Two · EZ as pi
May 30, 2017

+-17.5

Explanation:

First rearrange the equation to have all like terms on one side and unlike terms on the other:

7p^2 = 2135

Divide by 7 to get p on its own and then square root it.

p^2 = 305
sqrt(p^2)= +-sqrt(305)

p =+-sqrt(305)

= +-17.4642492

= +-17.5 (to 3 sf)

smendyka · EZ as pi
May 30, 2017

See a solution process below:

Explanation:

First, subtract color(red)(16) from each side of the equation to isolate the p term while keeping the equation balanced:

7p^2 + 16 - color(red)(16) = 2151 - color(red)(16)

7p^2 + 0 = 2135

7p^2 = 2135

Next, divide each side of the equation by color(red)(7) to isolate p^2 while keeping the equation balanced:

(7p^2)/color(red)(7) = 2135/color(red)(7)

(color(red)(cancel(color(black)(7)))p^2)/cancel(color(red)(7)) = 305

p^2 = 305

Now, take the square root of each side of the equation to solve for p while keeping the equation balanced. Remember, the square root of a number produces both a positive and negative result:

sqrt(p^2) = +-sqrt(305)

p = +-17.464 rounded to the nearest thousandth.

Related questions
See all questions in Use Square Roots to Solve Quadratic Equations
Impact of this question
2274 views around the world
You can reuse this answer
Creative Commons License