Answer:
7x+9y=45
Step-by-step explanation:
Standard equations always mean that you have to get x and y on one side so that they equal the coefficient.
Do this by adding the fraction that is combined with x to the other side where y is. The equation should now read 
Standard form cannot have fractions, so now you must multiply by the denominator (9) on both sides of the equation in order to cancel it out. Don't forget to multiply EACH variable by 9. This leads you to the answer.
Part 1:
Proportion: $7 every 2 days
Solve: He will earn 98 dollars if he does his chores every day for 2 weeks.
Solution as a sentence: To find the answer, you need to multiply seven, by fourteen.
Part 2:
Proportion: 2 bags last 5 days.
Solve: 8 bags of feed will last 20 days.
Solution in a sentence: To solve the problem, divide eight by two. Then multiply five by four.
Part 3:
Proportion: 3 eggs for every 4 hens.
Solve: 24 hens will lay 18 eggs.
Solution in a Sentence: If you divide twenty four by four, then multiply the answer by three, you will get your answer of eighteen eggs total.
Hope this helps you out. :)