Question

If one number is 80% of the other and 4 times
the sum of their squares is 656, then the
numbers are:
(a) 6,8 (b) 8, 10
(c) 16, 20 (d) 10, 15

Answer 1

$\sf{\large{Question:}}$



If one number is 80% of the other and 4 times
the sum of their squares is 656, then the
numbers are:


(a) 6,8
(b) 8, 10
(c) 16, 20
(d) 10, 15



____________________________________________________________



$\sf{\large{Answer:}}$


$\bf{Option \: b.\: 10 \: and \: 8}$



____________________________________________________________



$\huge{\mathfrak{\underline{\underline{Brainly \: Solution:}}}}$


▶ Let the number be x and $\dfrac{8}{10}$x.

$\sf \because 4 \bigg[ {x}^{2} + { \bigg( \dfrac{8}{10} x \bigg)}^{2} \bigg] = 656 \\ \\ \sf \to 4 \bigg[ {x}^{2} + \frac{{64x }^{2} }{100} \bigg] = 656\\ \\ \sf \to 4 [100 {x}^{2} + {64x}^{2} ] = 656 \times 100 \\ \\ \sf \to 4 \times 164 {x}^{2} = 65600 \\ \\ \sf \to 656x {}^{2} = 65600 \\ \\ \sf \to x {}^{2} = \frac{ \cancel{65600 }\: \: ^ { \large{100}} }{ \cancel{656}} \\ \\ \sf \to x {}^{ \cancel2} = 10 {}^{ \cancel2} \\ \\ \sf \dfrac{8}{10} \: of \: x \\ \\ \to \sf \dfrac{8}{10} \: of \: 10 \\\\ \to \sf 8$


$\huge \orange{ \boxed{ \boxed{ \sf{ \therefore x = 10}}}}$



✔✔ Hence, it is solved ✅✅.



$\huge \green{ \boxed{ \boxed{ \mathscr{THANKS}}}}$


____________________________________________________________

Answer 2

♣ Heÿ ♣

Question :
--------------

If one number is 80% of the other and 4 times
the sum of their squares is 656, then the
numbers are:
(a) 6,8 (b) 8, 10
(c) 16, 20 (d) 10, 15


Answer :
-------------


Option (b) 8,10


HöPe ïT hèLps