Question

EXERCISE 6.3
1. Find
(a) 35 - (20)
(b) (-15) - (-18)
(c) 23 - (- 12)
(d) 72 - (90)
(e) (-20) - (13)
(f) (-32) - (-40)
please tell me in method please​

Answer 1

As you know if you know so I tell you the rules of integers

+ + = +

- - = +

+ - = -

- + = -

(-10) = -10

(1) = +1

(a) 35 - (20) = 35 - + 20 = -15

(b) (-15) -(-18) = -15 + 18 = -3

(c) 23 - (-12) = 23 + 12 = +35

Answer 2

Solution :-

• (a) 35 - (20)

$\sf{ = (15 + 20) - 20}$

$\sf{ = 15 + (20 - 20)}$

$\sf{ = 15 + 0}$

$\rm{ = 15}$

• (b) 72 - (90)

$\sf{ = 72 - (72 + 18)}$

$\sf{ = (72 - 72) + (-18)}$

$\sf{ = 0 + (-18)}$

$\rm{ = -18}$

• (c) (-15) - (-18)

$\sf{ = -15 + 18}$

$\sf{ = -15 + (15 + 3)}$

$\sf{ = (-15 + 15) + 3}$

$\sf{ = 0 + 3}$

$\rm{ = +3 \: or \: 3}$

• (d) (-20) - 13

$\sf{ = -20 - 13}$

$\sf{ = -(20 + 13)}$

$\rm{ = -33}$

• (e) 23 - (-12)

$\sf{ = 23 + 12}$

$\rm{= 35}$

• (f) (-32) - (-40)

$\sf{ = -32 + 40}$

$\sf{ = (-32 + 32) + 8}$

$\sf{ = 0 + 8}$

$\rm{ = 8}$