URGENT MATH! What is x - y?

Question

have been trying to remember how to do this problem for while and I just can't! Please if anyone knows how to do this, I don't just want the answer I want to know how to do it. Please help :-)

x(squared) - y(squared) = 42 and x + y = 6, what is the value of x - y

Thank you all so much! I had forgotten that I needed to factor to solve it, it seems so simple now, :-) THANK YOU!

Answer 1

x^2-y^2=42 and x+y=6
first factor the first equation
(x-y)(x+y)=42 (this is something called a difference of squares basically when one thing squared minus another thing squared without a middle term factors to the first term plus the second times the first term minus the second(sorry if you don't understand)
(x-y)(6)=42 (substitute 6 for x+y)
x-y=7 (divide by 6)
Hope this helps

Answer 2

x^2 - y^2 = 42
(x + y)(x - y) = 42
if the (x + y) is 6 then the (x - y) factor must by 7 since
(6)(7) = 42

Answer 3

x^2-y^2=42 can be expressed as (x+y)(x-y)=42
since we know that x+y=6 we plug 6 in for x+y and we get 6(x-y)=42 which leads to x-y=42/6=7

Answer 4

OK

x^2 - y^2 =42
(x+y)(x-y) = 42 ; now you said x+y =6, so.....

6 (x-y) = 42
x-y = 42/6
x-y = 7

SO x-y = 7

Hope that helps!

Answer 5

x^2 + y^2 = 42
x + y = 6

so x = 6 - y and

( 6 - y )^2 + y^2 = 42

36 - 12y + y^2 + y^2 = 42
2y^2 - 12y + 36 = 42
y^2 - 6y + 18 = 21
y^2 - 6y -3 = 0

Solve for y, then use either of your initial equations to find x

Answer 6

x(squared) - y(squared)=(x+y)(x-y)=42
b/c (x+y)=6
so, x-y=7