Question

a+b is 10 and a square + b square us 58 find a cube + b cube
Plz answer
Tomorrow is my maths paper...
99 points u will got and also brainlist

Answer 1

so lets take your equations my friend
$a + b = 10 \\ a^2+b^2 = 58$
as you know $a^3 + b^3 = (a+b)(a^2-ab+b^2) = 10(58-ab)$
now we need $ab =?$
as $(a+b)^2=a^2+b^2+2ab$
$ab = \frac{(10^2 - 58)}{2} = 21$
Finally $a^3 + b^ 3 =10(58-21) = 370$

Answer 2

Hey...

$a + b = 10 \\ {a}^{2} + {b}^{2} = 58 \\ we \: know \: that \: {a}^{3} + {b}^{3} = (a + b) ( {a}^{2} + { b}^{2} - ab) \\ \\ so \: {(a + b)}^{2} - 2ab = {a}^{2} + {b}^{2} \\ 100 - 58 = 2ab \\ ab = 21 \\ \\ so \: {a}^{3} + {b}^{3} = 10 \times (58 - 21) \\ 10 \times 37 = 370$
Thanks☺