Question

(a+b =2) a-b = 10 than what is the value of (a+b)^2 and ab

Answer 1

a+b= 2
a-b= 10 (adding both equation)
2a= 12
a= 6

putting the value of a in equation 1
6+b=2
b= -4
so
(a+b)²= a²+b²+2ab
= (6+(-4))²
= (6-4)²
= 2²=4
ab= 6*-4= -24

Answer 2

$a + b = 2 - - - - (1) \\ a - b = 10 - - - - (2) \\ adding \: both \: equations \\ 2a = 12 \\ a = 6 \\ put \: a = 6 \: in \: eq.(1) \\ a + b = 2 \\ 6 + b = 2 \: \\b = 2 - 6 \\ b = - 4 \ \\ (a + b) {}^{2} \: = a {}^{2} + b {}^{2} + 2ab \\ (6 - 4) { }^{2} = \: 6 {}^{2} + ( - 4) {}^{2} - 2ab \\ 2 {}^{2} = 36 + 16 - 2ab \\ 4 - 52 = - 2ab \\ - 48 = - 2ab \\ ab \: = 48 \div 2 \\ ab = 24 \\ help \: it \: is \: helpful \: for \: you \: \\ please \: mark \: as \: a \: brainliest \: answer$
And
(a+b)^2 = 4