Question

help mee please.

If x-y=20, and x^2-y^2=50, what is the value of X

Answer 1

Replace y in the second equation with x-20 from the first equation.

Answer 2

x-y not x-20 Mertsj

Answer 3

How so?

Answer 4

@mertsj, are you using the elimination by substitution method

Answer 5

When you replace a variable, that means substitute something else for it.

Answer 6

ok. so now its
x^2 - (x-20)^2=50

Answer 7

yes

Answer 8

so after you distribute the negative sign it becomes
x^2(-x+20)^2=50

Answer 9

\[x^2-(x^2-40x+400)=50\]

Answer 10

\[x^2-x^2+40x-400=50\]

Answer 11

what did you just do.

Answer 12

\[40x=450\]

Answer 13

Expand (x-20)^2
Remove the parentheses by changing everything inside to its opposite.