Question

Find the value of x
a. 2
b. 4
c. 6
d. 8

Answer 1

B, 4

Explanation:

To do this you can use the Pathagaryos thereom a^2+b^2=c^2

So we have (x-2)^2+x^2=20

We can expand (x-2)^2 and get

x^2-4x+4

so we have x^2 -4x +4 + x^2=20

We can combine like terms and subtract 20 from both sides to get

2x^2-4x-16=0

We can factor this and get (2x+4)(x-4)

which means that x=4 and -2

Obviously the length can't be a negative and so we reject x= -2 and we get x=4

We can double check it and see that

(4-2)^2+4^2=20

and it does