Solve for z. Remember: you are solving for an unknown coefficient, not the value of the variable as a number.
-P(51 + z) = dz +84

Afactory buys 10% of its components from suppliers b and the rest from supplier c. it is known that 6% of the components it buys are faulty. of the components brought from suppliers a,9% are faulty and of the components bought from suppliers b, 3% are faulty. find the percentage of components bought from supplier c that are faulty.