Question

Afla nr. X din egalitatile de mai jos.
a). (8x5+6x9+X):9+312=323
b). 4x [(4xX-72)÷4+20]-64=20
c). 100-[250-5x (X-5)÷x3=40
d). 643-[(X-162)÷5+159]=454
e). [(3x X +4) x 2+5] x 3+5=170

Answer 1

a). (8x5+6x9+X):9+312=323
(40+54+X):9=323-312
(94+X):9=11
94+X=11×9
94+X=99
X=99-94
X=5

b). 4x [(4xX-72)÷4+20]-64=20
4x (4xX-72)÷4+20=20+64
4x (4xX-72)÷4+20=84
4x (4xX-72)÷4=84-20
4x (4xX-72)÷4=64
4x (4xX-72)=64×4
4x (4xX-72)=256
4×X-72=256:4
4×X-72=64
4×X=64+72
4×X=136
X=136:4
X=34

c). 100-[250-5x (X-5)÷3]=40
250-5x (X-5)÷3=100-40
250-5x (X-5)÷3=60
250-5x (X-5)=60×3
250-5x (X-5)=180
5x (X-5)=250-180
5x (X-5)=70
X-5=70:5
X-5=14
X=14+5
X=19


d). 643-[(X-162)÷5+159]=454
(X-162)÷5+159=643-454
(X-162)÷5+159=189
(X-162)÷5=189-159
(X-162)÷5=30
X-162=30×5
X-162=150
X=150+162
X=312


e). [(3x X +4) x 2+5] x 3+5=170
[(3x X +4) x 2+5] x 3=170-5
[(3x X +4) x 2+5] x 3=165
(3x X +4) x 2+5=165:3
(3x X +4) x 2+5=55
(3x X +4) x 2=55-5
(3x X +4) x 2=50
3x X +4=50:2
3x X +4=25
3x X=25-4
3x X=21
X=21:3
X=7

Dacă tu crezi că merit, astept coroana!