Question

Află nr necunoscut
a) 14562+23×(46+75) -a=4812
b) 491+d+47×47-718=5836
c) 420:(215-1000:b) +24×7=170

Answer 1

Explicație pas cu pas:

a)14 552+23×(46+75)-a=4 812

14 552+23×121-a=4 812

14 552+2 783-a=4 812

17 335-a=4 812

a=17 335-4 813

a=12 523

v:14 552+23×(46+75)-12 523=

14 552+23×121-12 523=

14 552+2 783-12 523=

17 335-12 523=

4 812

b)491+d+47×47-718=5 836

491+d+2 209-718=5 836

491+d+2 209=5 836+718

491+d+2 209=6 554

491+d=6 554-2 209

491+d=4 345

d=4 345-491

d=3 854

v:491+3 854+47×47-718=

491+ 3 854+2 209-718=

4 345+2 209-718=

6 54-718=

5 836

c)420:(215-1000-b)+24×7=170

420:(215-1 000-b)+168=170

420:(-785-b)+168=170

420:(-785-b)=170-168

420:(-785-b)=2

420:-785-b=2

-785-b=420:2

-785-b=210

b=-785-210

b=-995

Answer 2

Răspuns:

$a)\:14562+23*(46+75) - a=4812\\\\14562 + 23*121 - a = 4812\\\\14562 + 2783 - a = 4812\\\\17345 -a = 4812\\\\17345 = 4812 +a\\\\17345 -4812 = a\\\\ \boxed{a =12533}$

b)

$491+d+47*47-718=5836\\\\491+d+2209-718=5836\\\\d+1982 = 5836\\\\d = 5836-1982\\\\ \boxed{d = 3854}$

c)

$420:(215-1000:b) +24*7=170\\\\420:(215-1000:b) +168=170\\\\420:(215-1000:b)=170-168\\\\420:(215-1000:b) = 2\\\\420 =2 * (215-1000:b)\\\\420 = 430-2000:b\\\\420+2000:b = 430\\\\2000:b = 430-420\\\\2000:b = 10\\\\2000=10b\\\\b = 2000:10\\\\\boxed{b = 200}$