Question

Daca a la puterea 2 - b la puterea 2 = 180 si a - b =10 , atunci a + b =

Answer 1

${a}^{2} - {b}^{2} = 180$

$a - b = 10$

${a}^{2} - {b}^{2} = (a + b)( a- b)$

$(a + b)(a - b) = 180$

$(a + b) \times 10 = 180$

$a + b = 180 \div 10$

$a + b = 18$

$a = 18 - b$

$18 - b - b = 10$

$- b - b = 10 - 18$

$- 2b = - 8 \: | \div ( - 2)$

$b = 4$

$a = 18 - b$

$a = 18 - 4$

$a = 14$