1. State the problem: Find the cost to print 100,000 copies given the linear cost function $C = Ax + B$ where the cost for 10,000 copies is 5000 and for 15,000 copies is 6000. 2. Use the given information to form two equations: $$5000 = A\times 10000 + B$$ $$6000 = A\times 15000 + B$$ 3. Subtract the first equation from the second to eliminate $B$: $$6000 - 5000 = A(15000 - 10000)$$ $$1000 = 5000A$$ 4. Solve for $A$: $$A = \frac{1000}{5000} = 0.2$$ 5. Substitute $A$ back into the first equation to find $B$: $$5000 = 0.2\times 10000 + B$$ $$5000 = 2000 + B$$ $$B = 5000 - 2000 = 3000$$ 6. Write the cost function: $$C = 0.2x + 3000$$ 7. Find the cost for $x = 100,000$ copies: $$C = 0.2 \times 100000 + 3000 = 20000 + 3000 = 23000$$ Final Answer: The cost to print 100,000 copies is 23000.