Please help with 15.

-4

Step-by-step explanation:

If you look at the table closely for the value of x decreases by 2 like the first value is 7 then it goes to 5 then it goes to 3 then to 1, and if you look at the values of y it decreases by 20 like the first number is 66 then 46 then 26 then 6.

But in the table it asks the missing value of y when x is 0 not -1 so for difference of 1 instead of the usual 2 in the pattern the value of y would decrease by 10 instead of 20 so 6-10 would be -4

so the missing value of y is -4

where is the triangle?