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# Stuck on problem solving quadratic equation question.

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1. Hi there, struggling to understand how this question gets the answer.

So the area of the patio is 4m x 5m = 20m^2

The area of the whole thing would be (4 + x)(5 + x) = ? is the ? 20m^2 + 10m^2

Expanding that gives x^2 + 9x + 20 = ?

I'm sort of lost on how they get 4x^2 + 18x = 10
2. (Original post by jojo55)

Hi there, struggling to understand how this question gets the answer.

So the area of the patio is 4m x 5m = 20m^2

The area of the whole thing would be (4 + x)(5 + x) = ? is the ? 20m^2 + 10m^2

Expanding that gives x^2 + 9x + 20 = ?

I'm sort of lost on how they get 4x^2 + 18x = 10
(4+2x)(5+2x) because theres an x on either side of the patio.
3. (Original post by NotNotBatman)
(4+2x)(5+2x) because theres an x on either side of the patio.
Doh!

Now I can see it .

Thanks.
4. (Original post by jojo55)
Doh!

Now I can see it .

Thanks.
-20 because of the patio itself
5. (Original post by an_atheist)
-20 because of the patio itself
Cheers .

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