Question

Aflati numarul necunoscut:
a) 1730:[(21×b-33)–4]×20-16=185
b) [10+10×(a-10)]:10-10=10
c) 1200-(2×c+100):19+2500=3500


Va rooooog! Dau coroana primului raspuns!

Answer 1

c) 2×c=3500+1200×19-2500
2×c=22800-2500+3500
2×c=20300+3500
2×c=23800
c=23800÷2
c=11900
doar pe acesta lam stiut!

Answer 2

a)
1730:[(21×b-33)–4]×20-16=185
1730:[(21×b-33)–4]×20=185+16
1730:[(21×b-33)–4]×20=201
1730:[(21×b-33)–4]=201:20
1730:[(21×b-33)–4]=10,05
(21×b-33)–4=1730:10,05
(21×b-33)–4=172,139
21×b-33=172,139 +4
21×b-33=176,139
21×b=176,139+33
21×b=209,139
b=209,139 : 21
b=9,959 (aprox)


b)
[10+10×(a-10)]:10-10=10
[10+10×(a-10)]:10=10+10
[10+10×(a-10)]:10=20
10+10×(a-10)=20×10
10+10×(a-10)=200
10×(a-10)=200-10
10×(a-10)=190
a-10=190:10
a-10=19
a=19+10
a=29



c)
1200-(2×c+100):19+2500=3500
1200-(2×c+100):19=3500-2500
1200-(2×c+100):19=1000
(2×c+100):19=1200-100
(2×c+100):19=200
2×c+100=200×19
2×c+100=3800
2×c=3800-100
2×c=3700
c=3700:2
c=1850