Question

Determinati nr x,stiind ca a-b=6 si:
a)x+3×a-3×b=20
b)X×a-x×b+9a-9b=654
c)7×a-7*b+x=55
d)13+x-(5*a-5*b)=2011.

Answer 1

a) x + 3(a-b) = 20

x + 18 = 20

x = 2

b) x(a-b) + 9(a-b) = 654

6x + 54 = 654

6x = 600

x = 100

c) 7(a-b) + x = 55

42 + x = 55

x = 13

d) 13 + x(- 5(a-b)) = 2011

13 + x - 30 = 2011

x - 17 = 2011

x = 2028