How do you solve 5p ^ { 2} - 8p = 05p28p=0?

2 Answers
Mar 3, 2018

p=0p=0 and p=8/5p=85

Explanation:

Both terms have a pp in common, so we can factor that out. We get:

p(5p-8)=0p(5p8)=0

If the product of two things are equal to zero, either one or both of them must be equal to zero. So let's set them equal to zero. We get:

p=0p=0, and for the term in parenthesis:

5p-8=05p8=0

5p=85p=8

p=8/5p=85

Therefore, our two zeroes are p=0p=0 and p=8/5p=85

Mar 3, 2018

p=0p=0, or p=8/5p=85

Explanation:

Step one is to factor the left side of the equation. You can factor out a pp from each term, giving you p(5p-8)=0p(5p8)=0

From here, you can divide both sides by pp, or by 5p-85p8. I'll start with dividing by 5p-85p8. This gives us p=0p=0. That's your first solution, but not the only one.

Next, we'll divide both sides by pp. This gives us 5p-8=05p8=0
Add 88 to both side to get 5p=85p=8
Divide both sides by 55, and we have our other solution p=8/5p=85

You can check your work by plugging these values into your initial equation.
For p=0p=0,
5(0)^2-8(0)=05(0)28(0)=0
5(0)-0=05(0)0=0
0=00=0
So, p=0p=0 is correct.

For p=8/5p=85,
5(8/5)^2-8(8/5)=05(85)28(85)=0
5(48/25)-48/5=05(4825)485=0
48/5-48/5=0485485=0
0=00=0
So, p=8/5p=85 is also correct.