He would have 21 before he bought the 10 stamp because 31-10=21
70-3·6+9
Remember PEMDAS.
You must multiply the 3 and 6 together, and you would get 18.
Then, you subtract 18 from 70, which would give you 52.
And finally, you would add 9 to 52, getting 61 as your final answer.
i would start by simplifying the equation to get y by itself, you don't need to do this, but it makes it a little easier
y + 2 = 3 ( x + 4) distribute the 3 through the parenthesis
y + 2 = 3x + 12. subtract 2 from both sides
y = 3x +10
now to fill in the chart simply plug in the value of x to see what value of y it produces
y = 3(-2) +10
y = -6+10
y = 4
(-2,4)
y = 3(0) + 10
y = 0 + 10
y = 10
(0,10)
y = 3(2)+10
y = 6 + 10
y = 16
(2,16)
y = 3(4) + 10
y = 12 + 10
y = 22
(4,22)
The sequence is the Fibonacci sequence!
It works like this.
1+2=3
2+3=5
3+5=8
5+8=13
8+13=21
and so on.
