Question

3. Rezolvați, folosind metoda mersului invers, ecuația: a) (13•x-416:4):7=13; b) (123•x-1278):149 = 36; c) 6-5:[4-3:(2-2:x)]=1; d) 420:(160 - 1000 : x)+24.7=1 e) 1+{2-[3+(x-4).5]: 63.7=8; [(x+2°): 2° - 32:31.24 = 22 -​

Answer 1

Explicație pas cu pas:

• a. (13•X-416:4):7=13

13•X-416:4=13•7

13•X-416:4=91

13•X-416=91•4

13•X-416=364

13•X=364+416

13•X=780

X=780: 13

X=60

• b. (123•X-1278):149=36

123•X-1278=36•149

123•X-1278=5364

123•X=5364+1278

123•X=6642

X=6642:123

X=54

• c. 6-5:[4-3:(2-2:X)]=1

5:[4-3:(2-2:X)]=1+6

5:[4-3:(2-2:X)]=7

4-3:(2-2:X)=7•5

4-3:(2-2:X)=35

3:(2-2:X)=35+4

3:(2-2:X)=39

2-2:X=39•3

2-2:X=117

2:X=117+2

2:X=119

X=119•2

X=238

• d. 420:(160-1000:X)+24•7=1

(160-1000:X)+24•7=1•420

(160-1000:X)+24•7=420

(160-1000:X)+24=420:7

(160-1000:X)+24=60

160-1000:X=60-24

160-1000:X=36

1000:X=36+160

1000:X=196

X=196•1000

X=196000

• e. 1+{2-[3+(X-4)•5]:63•7=8

{2-[3+(X-4)•5]}:63•7=8-1

{2-[3+(X-4)•5]}:63•7=7

{2-[3+(X-4)•5]}:63=7:7

{2-[3+(X-4)•5]}:63=1

2-[3+(X-4)•5]=1•63

2-[3+(X-4)•5]=63

3+(X-4)•5=63+2

3+(X-4)•5=65

3+(X-4)=65:5

3+(X-4)=13

X-4=13-3

X-4=10

X =10+4

X=14

La ultimul n-am înțeles..

Sper că te-am ajutat!! :))