Question

rezolva necunoscutul

1. (a-70)×3-312=249

2. (a+70)×3+312=401

3. (x+15)×10-100:5+90=10

4. (x+20):12+68=78

5. (x+282-75):2=104

6. a×4:10+101=133
Va rog repede.Dau coroana

Answer 1

1.
(a-70)×3-312=249
(a-70)×3=249+312
(a-70)×3=561
a-70=561:3
a-70=187
a=187+70
a=257


2.
(x+15):3+312=401
(x+15):3=401-312
(x+15):3=89
x+15=89×3
x+15=267
x=267-15
x=252

3.
(x-15)×10-100:5+90=100
(x-15)×10-20=100-90
(x-15)×10-20=10
(x-15)×10=10+20
(x-15)×10=30
x-15=30:10
x-15=3
x=3+15
x=18

4.
(x+20):12+68=78
(x+20):12=78-68
(x+20):12=10
x+20=10×12
x+20=120
x=120-20
x=100


5.
(x+282-75):2=104
x+282-75=104×2
x+282-75=208
x+282=208+75
x+282=283
x=283-282
x=1


6.
a×4:10+101=133
a×4:10=133-101
a×4:10=32
a×4=32×10
a×4=320
a=320:4
a=80