Question

Aflați x din egalitățile: a)320:{[340-(120-4×x)]÷10+6}=10;b){250-[175:(720:x+15)+3]×5}:10=20;c)30-{[(2×x-8)×2-12]:4-1}×10=20;d)49-[4275:19+(242×54-34×x):38]:12=30.

Answer 1

a)320:{[340-(120-4xX)]:10+6}=10
{[340-(120-4xX)]:10+6}=320:10=32
[340-(120-4xX)]:10=32-6=26
340-(120-4xX)=26x10=260
120-4xX=340-260=80
4xX=120-80=40
x=40:4
x=10

b){250-[175:(720:x+15)+3]x5}:10=20
{250-[175:(720:x+15)+3]x5}=20x10=200
[175:(720:x+15)+3]x5=250-200=50
[175:(720:x+15)+3]=50:5=10
175:(720:x+15)=10-3=7
720:x+15=175:7=25
720:x=25-15=10
x=720:10
x=72

c)30-{[(20xX-8)x2-12]:4-1]x10=20
{[(20xX-8)x2-12]:4-1}x10=30-20=10
[(20xX-8)x2-12]:4-1]=10:10=1
[(20xX-8)x2-12]:4=1+1=2
(20xX-8)x2-12=2x4=8
(20xX-8)x2=8:2=4
20x-8=4:2=2
20x=2+8=10
x=10:20
x=0.5

d)49-[4275:19+(242x54-34xX):38]:12=30
49-[4275:19+(13068-34xX):38]:12=49-30=19
4275:19+(13068-34xX):38=19x12=228
4275:19+(13068-34xX)=228x38=8664
225+(13068-34xX)=8664
13068-34xX=8664-225=8439
34x=13068-8439=4629
x=4629:34
x=136.14

Answer 2

a)
320:{[340-(120-4×x)]:10+6}=10
{[340-(120-4×x)]:10+6}=320:10=32
[340-(120-4×x)]:10=32-6=26
[340-(120-4×x)]=26x10=260
340-(120-4×x)=260
120-4×x=340-260
120-4×x=80
4×x=120-80
4×x=40
x=40:4
x=10
b)
{250-[175:(720:x+15)+3]×5}:10=20
{250-[175:(720:x+15)+3]×5}=20×10=200
[175:(720:x+15)+3]x5=250-200=50
[175:(720:x+15)+3]=50:5=10
175:(720:x+15)=10-3=7
(720:x+15)=175:7=25
720:x+15=25
720:x=25-15
720:x=10
x=720:10
x=72
c)
30-{[(2×x-8)×2-12]:4-1}x10=20
{[(2×x-8)x2-12]:4-1}x10=30-20=10
{[(2×x-8)×2-12]:4-1}=10:10=1
[(2×x-8)×2-12]:4=1+1=2
[(2×x-8)x2-12]=2x4=8
(2×x-8)x2=8+12=20
(2×x-8)=20:2
2×x-8=10
2×x=10+8
2×x=18
x=18:2
x=9
d)
49-[4275:19+(242×54-34×x):38]:12=30
[225+(13068-34×x):38]:12=49-30=19
[225+(13068-34×x):38]=19x12=228
(13068-34×x):38=228-225=3
(13068-34×x)=3x38=114
34×x=13068-114
34×x=12954
x=12954:34
x=381