a) 4
820:4 - [(45: 9+8 x 3) 3 - 28:4x2] =
812:4 - [10 x 9: (4 + 3 x 11 + 48:6) +9] =
905:5+ [ 12 x 8 - (3 + 2 x 15 - 32:8) - 7] =
Determină valoarea lui ,,a":
a - 28+ [14 x 5: 7- (21: 3)] + 175 = 500
a + 19 - [24 x 5:2-(163)] + 238 = 480
a - 57 + [29 x 3 x 5 - (25 x 8)] + 602 = 865
a +49- (17 x 6 x 9 - (92 x 7)] + 318 = 443​

Răspuns :

Explicație pas cu pas:

205-[(5+24)×3-14]=205-(29×3-14)=205-(87-14)=205-73=132

203-[90:(4+33+8)+9]=203-(90:45+9)=203-11=192

181+[96-(3+30-4)-7]=181+(96-29-7)=181+60=241

a-28+(70:7-7)+175=500

a-28+3+175=500

a+150=500

a=500-150

a=350

a+19-(60-163)+238=480

a+19-(-103)+238=480

a+19+103+238=480

a+360=480

a=480-360

a=120

a-57+(435-200)+602=865

a-57+235+602=865

a+780=865

a=865-780

a=85

a+49-(918-644)+318=443

a+49-274+318=443

a+93=443

a=443-93

a=350