# I could use a hand, mathematic lads and legends

#### DMurphy33

##### New member
Yo, my class is retaking a maths test tomorrow. There’s one question I didn’t understand at all in the previous test, the teacher has yet to go through it, and I could use a hand. First time using a site like this so I hope I’m doing this right. Cheers lads

17x-5x2

#### Romsek

##### Full Member
I don't see any question.

#### Subhotosh Khan

##### Super Moderator
Staff member
Yo, my class is retaking a maths test tomorrow. There’s one question I didn’t understand at all in the previous test, the teacher has yet to go through it, and I could use a hand. First time using a site like this so I hope I’m doing this right. Cheers lads

17x-5x2
Do you mean lassies in this group are not invited to answer your query??

#### DMurphy33

##### New member
Do you mean lassies in this group are not invited to answer your query??
My friend, the lassies are the legends.
Sincerely, a girl attending a girls only secondary school

#### Subhotosh Khan

##### Super Moderator
Staff member
Yo, my class is retaking a maths test tomorrow. There’s one question I didn’t understand at all in the previous test, the teacher has yet to go through it, and I could use a hand. First time using a site like this so I hope I’m doing this right. Cheers lads

17x-5x2
You did not pose a question yet - just wrote a function of 'x'!!

What do you need to answer from that function?

#### pka

##### Elite Member
You posted in beginning algebra.
So we assume you are to solve the equation $$\displaystyle 17x-5x^2=0$$
$$\displaystyle 17x-5x^2=0\\x(17-5x)=0\\x=0\text{ or }x=\dfrac{17}{5}$$
If this is an incorrect reading then tell us what it is.

#### JeffM

##### Elite Member
To expand on pka's answer, if you have an equation of the form

$$\displaystyle g(x) * h(x) = 0 \implies g(x) = 0 \ne h(x) \text { or } h(x) = 0 \ne g(x) \text { or } g(x) = 0 = h(x).$$

This is called the zero-product property. Therefore

$$\displaystyle 17x - 5x^2 = 0 \implies x(17 - 5x) = 0 \implies$$

$$\displaystyle x = 0 \text { or } 17 - 5x = 0 \implies x = 0 \text { or } 5x = 17 \implies$$

$$\displaystyle x = 0 \text { or } x = \dfrac{17}{5}.$$