4. simplify the expression using the distributive property.
9(4y - 7)

36y - 63

Step-by-step explanation:

Brackets in maths mean multiplying the numbers inside the bracket by the outside

9(4y - 7)

First seperate them:

9 × 4y and 9 × -7

Make sure to remember that terms and number always come with the symbol before it, so 4y - 7 means +4y and -7. Not 7, if there's nothing there then it's positive.

Now multiply, 9 × 4y = 36y, we're multiplying so terms can come together.

and 9 × -7 = -63

Remember positive multiplied by a negative. is a negative

Now we put the answers together however, this isn't multiplying and 36y and 63 aren't like terms so they stay separate. there is a sign before the -63 so it subtracting so the final answer is 36y - 63

golden rule for multiplying:

a positive and a negative make a negative answer - × + = -

a positive and a positive make a positive

make a positive + × + = +

a negative and negative make a positive

- × - = +

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.