Question

Please help some1
i need help
Question below

Answer 1

If x + y = 1 and x^3 + x^3 = 19 find value of x^2 + y^2

Answer 2

x^3 + x^3 = 19 ?

2x^3 = 19
x^3 = 19/2
x = cubed root of 19/2

u can substitute this into the first equation x + y = 1 to solve for y, then you can solve for x^2 + y^2

Answer 3

opps i meant x^3 + y^3 =19

Answer 4

i thought thats what u meant thats why i put a ? after it :)

Answer 5

yes
(a + b)(a^2 - ab + b^2)

Answer 6

Great :)
a³ + b³ = (a + b)(a² - ab + b²)
19 = 1 (a² - ab + b²)

Answer 7

umm ok... i still dont think i get the question

Answer 8

i would just use substitution

Answer 9

how :P

Answer 10

let y = 1 - x

then y^3 = (1 - x)^3

expand it out

then you can write x^3 + (1 - x)^3 = 19
should come out nicely

Answer 11

a² + b² - ab = (a + b)² - 2ab -ab
19 = 1 - 3ab
-> ab = -18/ 3 = -6