Answer:
see explanation
Step-by-step explanation:
The diagrams show triangular figures
The first figure has 1 dot
The second has 1 + 2 = 3 dots
The third has 3 + 3 = 6 dots
The fourth has 6 + 4 = 10 dots
Note the pattern is + 2 , + 3, + 4
Thus the fifth pattern is 10 + 5 = 15 dots
This is the concept of algebra. The value of x three times less than the value of 45-10x will be as follows;
The value of x three times is:
3x
subtracting 45-10x we get:
3x-(45-10x)
3x+10x-45
13x-45
the answer is:
13x-45
