我想問(-3)+(-2)-(-4)+(-1)這類數、一個圖形的angles和7X－2y這類數應該點做

Remember the following:
+(+a) = +a
+(-a) = -a
-(+a) = -a
-(-a) = a.
So
+(-3) = -3
+(-2) = -2
-(-4) = +4
+(-1) = -1
So the expression becomes -3 -2 +4 -1 = 4 - 6 = -2.