A <em>factor</em> is a number that your number is divisible by.
19 has two factors: 19 and 1.
23 also has two factors: 23 and 1.
21 has four factors: It is divisible by 21 and 1, but also by 3 and 7.
25 has three factors: It is divisible by 25, 1, and 5.
We need a number less than 19 that has five or more factors.
What we can do is multiply a bunch of numbers together (so that we know that our number will be divisible by them) to give it a lot of factors.
Let's try 2 × 2 × 3. This gives us 12.
12 has <em>six</em> factors: 12, 1, 2, 6, 3, and 4.
Answer:
D
Step-by-step explanation:
(7 × 10-7) × 0.06
7 × 0.06 × 10^-7
0.42 × 10^-7
4.2 × 10^-8
Answer:
15/10, 30/20, 60/40, 120/80, 240/160, 480/320
Step-by-step explanation:
The number of push-ups is 2/3 the amount of sit-ups, so the ratio of sit-ups to push-ups is 3:2.
The easy way to do this is to double both 15 and 10 so your answer will stay an equivalent ratio. You will always have a 3:2 ratio this way.
2.1x + 4.2y = 14.7 is the same as x + 2y = 7 (divide both sides by 2.1)
-5.7x-1.9y=-11.4 is the same as 3x + y = 6 (divide both sides by -1.9)
Rearrange the first equation to get x = 7 - 2y and substitute into the second equation, 3(7 - 2y) + y = 6, 21 - 6y + y = 6, 5y = 15, y = 3
Substitute y = 3 into the first equation x + 2(3) = 7, x = 1
x = 1 and y = 3
by replacing 
, and then, interchanging 
and 
:
when 
