185k views
1 vote
What is the value of x in the diagram?

What is the value of x in the diagram?-example-1
User Grekkq
by
8.1k points

1 Answer

1 vote

Answer:

5

Explanation:

Pythagoras : a^2 + b^2 ≈ c^2

so, x^2 + (2x+2)^2 = (2x+3)^2

=> x^2 + 4x^2 + 8x + 4 = 4x^2 + 12x + 9

=> x^2 = 4x + 5

=> x^2 - 4x - 5 = 0

now solve the quadratic equating. a little bit of creative thinking and trying with the options of a (x-a)×(x+b)=0 approach (multiplying and adding of factors need to give us -5 but only -4x in the result, so we try a=-5 but then b=1 as "correcting" factor), and yes

(x-5)×(x+1) = x^2 - 4x - 5 = 0

this is only true, if at least one of the multiplication factors are 0.

so, x-5=0 or x+1=0. or both, but that is not possible.

x-5=0, when x=5.

x+1=0, when x=-1

-1 as the length of a side does not make any sense.

so, the only valid solution is x=5

User Mkuse
by
7.8k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories