standard_description: Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
problem_activity: Task
A government buys $x$ fighter planes at $z$ dollars each,
and $y$ tons of wheat at $w$ dollars each. It spends a total of $B$
dollars, where $B = xz + yw$. In (a)–(c), write an
equation whose solution is the given quantity.
The number of tons of wheat the government can afford to buy if it
spends a total of \$100 million, wheat costs  \$300 per ton, and it must
buy 5 fighter planes at \$15 million each.
The price of fighter planes if the government bought 3 of them, in addition to $10,\!000$ tons of wheat at \$500 a ton, for a total of \$50 million.
The price of a ton of wheat, given that a fighter plane costs $100,\!000$ times as much as a ton of wheat, and that the government bought 20 fighter planes
and $15,\!000$ tons of wheat for a total cost of
\$90 million.


aligns: no