Question

daca a-3b=9, aflati x din relatiile:

a) x+a-9b=31

b) 2x+2a-6b=36

c) 32-x+ 7a-21b=42

Answer 1

a) x+3( a-3b)=31 => x+3×9= 31 => x+27= 31 => x= 31-27 => x= 4
b) 2x+2( a-3b)= 36 => 2x+2×9=36 => 2x+18= 36 => 2x= 36-18 => 2x=18 => x= 9
c) 32-x+7( a-3b)= 42 => 32-x+7×9= 42 => 32-x+63= 42 => -x= -53 => x= 53