HwaZiobro845
HwaZiobro845 HwaZiobro845
  • 04-06-2015
  • Mathematics
contestada

If x² - y² = 55, and x - y = 11, then y =
a. 8
b. 5
c. 3
d. -8
e. -3

Respuesta :

mumsy
mumsy mumsy
  • 04-06-2015
x^2-y^2=55
this means that 
(x+y)(x-y)=55
we know that x-y=11 so we can write
(x+y)(11)=55
x+y=55/11 we divide by 11 and we obtain 
x+y=5

x-y=11 this means
x=y+11 we replace in the other equation (x+y=5)

y+11+y=5
2y=5-11
2y=-6
y=-3
and you find out that also 
x=8

Answer Link

Otras preguntas

"We are Wombats, Woozy, wicked Wombats," is an example of: * ​
The ratio of sam's age to Hank's age is 5 to 3.if the sum of their ages is 24, how old is Hank? a. 21 b. 9 c. 19 d. 15
If the circumference of the truck wheel is 37.68, what is the radius?
What were the benefits of changing the dam's construction? Check all that apply. It would deliver more water for irrigation. It would help protect homes from ri
20 points for help please! Thanks! I think it's B, am I right or wrong?
With little or no water in the region, why do people still fight for control of the Middle East? A. Oil B. Rubber C. Titles D. Glory
Help again plz I need work shown
Explain how nitrogen in the atmosphere ends up in an animal?
hello!!! i’ll give brainliest if you want but please answer correctly
I'm in the middle of the quiz and would love some help, thanks! ​