Question

if a+b=6 and a-b=4 find ab

Answer 1

given, a+b=6---(1)

a-b=4---(2)

adding (1) and (2) we get

2a=10

a=5

substitute in (1)

b=6-a=6-5=1

b=1

ab=(5)(1)=5


I hope this will help u :)

Answer 2

b=1
a=5 
a*b =20 if we use elimination method u would get answer in simple manner