Question

1) calcule
a) 10% de 850
b) 20% de 500
c) 50% de 75
d) 100% de 175
e) 25% de 200
f) 30% de 120
g) 15% de 80
com cálculo ​

Answer 1

a) 10% de 850

REGRA DE TRÊS

850 ------- 100%

x ------- 10%

100x = 850×10

100x = 8500

x = 8500 / 100

x = 85

b) 20% de 500

REGRA DE TRÊS

500 ------- 100%

x ------ 20%

100x = 500×20

100x = 10000

x = 10000/100

x = 100

c) 50% de 75

REGRA DE TRÊS

75 ----- 100%

x ----- 50%

100x = 75×50

100x = 3750

x = 3750/100

x = 37, 5

d) 100% de 175

REGRA DE TRÊS

175 ------ 100%

x ------ 100%

100x = 175×100

100x = 17500

x = 17500/ 100

x = 175

e) 25% de 200

REGRA DE TRÊS

200 ------- 100%

x -------- 25%

100x = 200×25

100x = 5000

x = 5000/100

x = 50

f) 30% de 120

REGRA DE TRÊS

120 ------- 100%

x ------ 30%

100x = 120×30

100x = 3600

x = 3600/100

x = 36

g) 15% de 80

REGRA DE TRÊS

80 -------- 100%

x -------- 15%

100x = 80×15

100x = 1200

x = 1200/100

x = 12

Answer 2

1) calcule
a) 10% de 850
= 10/100 . 850
= 1/10 . 850
= 85
_____________

b) 20% de 500
= 20/100 . 500
= 2/10 (:2)/(:2) . 500
= 1/5 . 500
= 100

_______________
c) 50% de 75
= 50/100 . 75
= 5/10 (:5)/(:5) . 75
= 1/2 . 75
= 37,5

______________

d) 100% de 175
= 100/100 . 175
= 175
______________
e) 25% de 200
= 25/100 . 200
= 25.2
= 50
_____________
f) 30% de 120
= 30/100 . 120
= 3/10 . 120
= 3.12
= 36
_____________
g) 15% de 80

= 15/100 . 180
= 15/10 (:5)/(:5) . 18
= 3/2 . 18
= 18/2 . 3
= 9.3
= 27