Answer:
See below.
Step-by-step explanation:
a.
The first figure has 1 square. The second figure has a column of 2 squares added to the left. The third figure has a column of 3 squares added to the left. Each new figure has a column of squares added to the left containing the same number of squares as the number of the figure.
b.
Figure 10 has 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55 squares.
c.
The formula for adding n positive integers starting at 1 is:
1 + 2 + 3 + ... + n = n(n + 1)/2
For figure 55, n = 55.
n(n + 1)/2 = 55(56)/2 = 1540
d.
Let's use the formula set equal to 190 and solve for n. If n is an integer, then we can.
n(n + 1)/2 = 190
n(n + 1) = 380
We know that 380 = 19 * 20, so n = 19.
Answer: yes
e.
Use the formula above,
S = n(n + 1)/2, where S is the sum.
f.
n(n + 1) = 1478
38 * 39 = 1482
37 * 38 = 1406
Answer:
blue is red
Step-by-step explanation:
Answer:
1 3/7 quarts should be drained off and replaced with pure antifreeze.
1 3/7 ≈ 1.4286
Current amount of antifreeze in quarts is -
30/ 100 × 10 = 3
40% ---> 4 quarts
Let the amount drained of and replaced with antifreeze be x-
The amount left after draining off is 10 − x.
The amount of antifreeze is 30/ 100 (10−x).
30/100(10-x)+x=4
3-3/10x+x=4
3+x(1-3/10)=4
x=1*10/7=1 3/7 quarts
check;
10- 1 3/7 = 8 4/7
=(30/100*8 4/7)+1 3/7
=(3/10 * 60/7) + 10/7
=3*6/7 + 10/7
=28/7
=4
4 liters of pure antifreeze is mixed into 10 quarts.
Answer: $2
Step-by-step explanation: 20 percent of 10 is 2
Hope I did this right
