Question 72259
0.3(z-10) - 0.5z =-6 
On the left side of the equal sign, use the distributive property
to get rid of the parenthesis:
0.3z-0.3*10 - 0.5z = -6
Combine "like" terms on the left side:
-0.2z-3 =-6
Add 3 to both sides to get:
-0.2z = -3
Divide both sides by -0.2 to get:
z=15
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Cheers,
Stan H.