Cho a,b € Z. Tìm x€ Z sao cho:
a, x – a = 2
b, x + b = 4
c, a – x = 21
d, 14 – x = b + 9
Cho a,b € Z. Tìm x€ Z sao cho: a, x – a = 2 b, x + b = 4 c, a – x = 21 d, 14 – x = b + 9
By Alice
By Alice
Cho a,b € Z. Tìm x€ Z sao cho:
a, x – a = 2
b, x + b = 4
c, a – x = 21
d, 14 – x = b + 9
$\text{Cho a,b € Z. Tìm x€ Z sao cho :}$
$\text{a, x – a = 2}$
`->` $\text{x = 2 + a}$
$\text{b, x + b = 4}$
`->` $\text{x = 4 – b}$
$\text{c, a – x = 21}$
`->` $\text{x = a – 21}$
$\text{d, 14 – x = b + 9}$
`->` $\text{x = 14 – ( b + 9 )}$
`->` $\text{x = 14 – b – 9}$
`->` $\text{x = 5 – b}$
a, x – a = 2
⇒ x = 2 + a
b, x + b = 4
⇒ x = 4 – b
c, a – x = 21
⇒ x = a – 21
d, 14 – x = b + 9
⇒ x = 14 – ( b + 9 )
x = 14 – b – 9 = 5 – b
$@yenngoc$