I have two questions: first question is : [ 8(6-1)-1]-[2-(5-2)] i got 40 as my answer is this right? And second question is -y + - 80 an equivalent expression to -(y+80)? Because I got

-y + - 80.

yes! they are both correct! good job!

wait! i got 45 for the 1st one

No, 40 is right.

[8(6 - 1) - 1] - [2 - (5 - 2)]

[8(5) - 1] - (2 - 3)

40 - 1 - (-1)

40

Let's break down your questions one by one:

First question: [8(6-1)-1]-[2-(5-2)]. To solve this expression, we need to follow the order of operations, which is commonly known as PEMDAS (Parentheses, Exponents, Multiplication/Division, and Addition/Subtraction).

Step 1: Start with the innermost parentheses, which is (6-1). 6-1 equals 5.
Expression so far: [8(5)-1]-[2-(5-2)]

Step 2: Next, we evaluate the next set of parentheses (5-2) within the second set of parentheses. 5-2 equals 3.
Expression so far: [8(5)-1]-[2-3]

Step 3: Moving on to the multiplication, we simplify 8(5), which equals 40.
Expression so far: [40-1]-[2-3]

Step 4: Continuing with the subtraction inside each set of brackets:
[40-1] equals 39,
[2-3] equals -1.
Expression so far: 39-(-1)

Step 5: Finally, we subtract the values: 39 - (-1) equals 40.
So, your answer of 40 is correct!

Second question: Is -y + -80 an equivalent expression to -(y+80)?
To determine if these two expressions are equivalent, we can distribute the negative sign in the second expression.

In -(y+80), we distribute the negative sign to both terms inside the parentheses:
-(y+80) equals -y - 80

Comparing this with -y + -80, we can see that both expressions are indeed equivalent.

Therefore, your answer of -y + -80 is correct!