Question

Which of the following will give answer with negative sign
(a) – 48 + 79
(b) – 40 + 40
(c) – 48 + 30
(d) 48 + ( - 39 )

Answer 1

c will give negative sign i.e. -48+30=-18

Answer 2

Answer:

Option c has negative value.

Step-by-step explanation:

Here we want to find which term will give answer with negative sign.

By option test we can find the answer.

Option -a:

$- 48 + 79 = 31$

Option -b:

$- 40 + 40 = 0$

Option-c:

$- 48 + 30 = - 18$

Option -d:

$48 + ( - 39) = 48 - 39 = 9$

Here option a,b,d don't have negetive value.

Only option c has negative value.

This is a problem of Algebra,

Some important formulas of Algebra,

(a + b)² = a² + 2ab + b²

(a − b)² = a² − 2ab − b²

(a + b)³ = a³ + 3a²b + 3ab² + b³

(a - b)³ = a³ - 3a²b + 3ab² - b³

a³ + b³ = (a + b)³ − 3ab(a + b)

a³ - b³ = (a -b)³ + 3ab(a - b)

${a}^{2} - {b}^{2} = (a + b)(a - b)\\{a}^{2} + {b}^{2} = {(a + b)}^{2} - 2ab\\{a}^{2} + {b}^{2} = {(a - b)}^{2} + 2ab\\{a}^{3} - {b}^{3} = (a - b)( {a}^{2} + ab + {b}^{2} )\\{a}^{3} + {b}^{3} = (a + b)( {a}^{2} - ab + {b}^{2} )$