Question

How do I show my 11year old. A+b=8 A-b=6

Answer 1

Solution-

a+b=8 ---- equation 1

a-b=6 ---- equation 2

$a + b = 8 \\ a = 8 - b$

Putting the value of a in equation 2.

$a - b = 6 \\ 8 - b - b = 6 \\ - 2b = - 2 \\ b = 1$

Putting the value of b in equation 1.

$a + b = 8 \\ a + 1 = 8 \\ a = 7$

So, a = 7 and b=1

Answer 2

I assume that you need a solution for them :

The given equations are

a + b = 8 ..... (1)

a - b = 6 ..... (2)

Simply we add the two equations:

(a + b) + (a - b) = 8 + 6

or, a + b + a - b = 14

or, 2a = 14, since b - b = 0

or, a = 7 [ divide both sides by 2 ]

Putting a = 7 in (1) no. equation, we get

7 + b = 8

or, b = 8 - 7

or, b = 1

Therefore the required solution is a = 7, b = 1.