1. The two equations follow the slope-intercept form which y=mx + b. They have the same y-intercept which is equal to 900.
2. Suppose x= 10
Plan Alpha: y=-7x+900=-7(10)+900=830
Plan Foxtrot: y = -17x+900 = -17(10)+900=730
Between the 2 plans, the lower value is 730. Plan Foxtrot is better for reduction of pollution.
3. The city council should choose Plan Foxtrot because the reduction of pollution is much greater. Their goal would be reached faster if they go with faster reduction of pollution.
Since we know that a number is divisible by 3 if the sum of all digits is divisible by 3.
Let us check which digits will make 371? divisible by 3.
11 is not divisible by 3.
Now let us check other digits as well.
12 is divisible by 3.
15 is also divisible by 3.
18 is divisible by 3 as well.
Therefore, 1, 4 and 7 in tenth place will make our number divisible by 3 and our numbers will be 3711, 3714 and 3717.
9,11,14
the pattern is add one then add two then add three