evaluate the expression when a=2 and y= -7. -a + 8y

Sure, let's evaluate the expression step by step:

The expression is -a + 8y.

Step 1: Substitute the given values of a and y into the expression. So, -a becomes -2 and 8y becomes 8*(-7).

Step 2: The expression now becomes -2 + 8*(-7).

Step 3: Now, calculate the multiplication part first according to the order of operations (BIDMAS/BODMAS/PEDMAS). So, 8*(-7) equals -56.

Step 4: The expression now becomes -2 - 56.

Step 5: Finally, calculate -2 - 56 which equals -58.

So, the value of the expression -a + 8y when a=2 and y=-7 is -58.