Answer:

21,28,36,45

Step-by-step explanation:

1,(+2)3,(+3)6,(+4)10,(+5),15

Answer:

             These set of numbers are called patterns. To find out what the next term in the sequence is, you need to find the rule. The rule is how you find how to find the next term in the sequence. For this problem, our sequence is 1, 3, 6, 10, 15, and (x). The letter (x) represents an unknown value or number. So, let's solve for the value of (x) now!

• The next one number in her pattern are: 21,
• The next two numbers in her pattern are: 21 and 28
• The next three numbers in her pattern are: 21, 28 and 36
• The next four numbers in her pattern are: 21, 28, 36, and 45.
• The rule in this pattern is that the pattern is the triangular number sequence.