Question

If a+b= 6 and a-b= 4 . Find ab

Answer 1

a+b=6 is 1st equation

a-b=4 is 2nd equation

add both

a+b+a-b=4+6

2a=10

a=10÷2

a=5

b=1(5+b=6, b=6-5, b=1)

ab=5x1=5