a,
\(7,3.x+x.2,7-x=405\)
\(x.\left(7,3+2,7-1\right)=405\)
\(x.9=405\)
\(x=405:9=45\)
a) 7,3 * x + x * 2,7 - x = 405
9 * x = 405
x = 45
b) x,x + x * 8,9 = 60
x + 0,1 * x + x * 8,9 =60
10 * x = 60
x = 6
a) 7,3 * x + x * 2,7 - x = 405.
= 7,3 * x + x* 2,7 - x *1= 405.
= (7,3+2,7-1)*x= 405.
= 9*x =405
x= 405: 9 = 45
b)