Question

Afla numerele necunoscute a) (a-180)×10=200. b) 30×6-16:2-b=19 c) (c+15):5=64:8

Answer 1

a) (a-180)×10=200, 10a-1800=200, 10a=200+1800, 10a=2000, a=200.

b) 30×6-16÷2-b=19, 180-8-b=19, 172-b=19, -b=19-172, -b=-153, b=153.

c) (c+15)÷5=64÷8, (c+15)×8=64×5, 8c+120=320, 8c=320-120, 8c=200, c=25.

Answer 2

a) 
(a-180)=200:10
a-180=20
a=20+180
a=200

b) 
180-8-b=19
172-b=19
b=172-19
b=153

c)
(c+15):5=8
c+15=8x5
c+15=40
c=40-15
c=25