Question

Question from class 9 mathematics. Please solve and I will mark you brainliest.

Answer 1

Answer:

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

a+b = 10

${a}^{2} + {b}^{2} = 58$

Putting the value in the formula

100 = 58 + 2ab

100-58 = 2ab

42 = 2ab

$\frac{42}{2} = ab$

21 = ab.

${(a + b)}^{3} = {a}^{3} + {b}^{3} + 3ab(a + b)$

${a}^{3} + {b}^{3} = {(a + b)}^{3} - 3ab(a + b)$

${(a + b)}^{3} = {10}^{3} - 3(21)(58)$

=1000 - 3654

= -2654