1 1
2 3
3 6
4 10
5 15
6 21
7 28
8 36
9 45
10 55
11 66
12 78
13 91
14 105
15 120
16 136
17 153
18 171
19 190
20 210
21 231
22 253
23 276
24 300
here is a spreadsheet to help you understand the stair problem notice for 1 step 1 block, 2 step, 3 block, 3 step, 6 block and so on notice the blocks for the number of a step is that step plus all the other blocks needed to make all the one(s) below it. Notice it takes 105 blocks to make 14 steps.
So if you are familiar with the summation process you would add the number that go with that stair with all the stairs below it. example step 5 blocks would be 5 + 4 + 3 + 2 +1 or 15 blocks. I hope this gets you started. The second part I do not understand the problems because they are not equations. NO equal signs
glad if it helps
Addends are any of the numbers added together in an equation.
The only time their grouping would matter would be if there were parentheses used to alter the normal Order of Operations.
For ex:
2 - (8 + 3) here, the 8 and 3 have to be grouped together before doing the subtraction.
Any addition problem without parentheses can be used for one where the grouping doesn't matter
The answer to your question is x = 8
Answer:
378.5 or just 378
Step-by-step explanation:
This is a linear model with x representing the number of generations that's gone by, y is the number of butterflies after x number of generations has gone by, and the 350 represents the number of butterflies initially (before any time has gone by. When x = 0, y = 350 so that's the y-intercept of our equation.)
The form for a linear equation is y = mx + b, where m is the rate of change and b is the y-intercept, the initial amount when x = 0.
Our rate of change is 1.5 and the initial amount of butterflies is 350, so filling in the equation we get a model of y = 1.5x + 350.
If we want y when x = 19, plug 19 in for x and solve for y:
y = 1.5(19) + 350
y = 378.5
Since we can't have .5 of a butterfly we will round down to 378
