Question

Karissa says that to represent the expression $-7\ -\ \left(-9\right)$ on a number line, she should start at $-7$ and move $9$ units to the left.

Is she correct? Explain why or why not

Answer 1

No, Karissa is not correct. To represent the expression -7 - (-9) on a number line, we start at -7 and move 9 units to the right.

Step-by-step explanation:

No, Karissa is not correct. To represent the expression $-7 - (-9)$ on a number line, we start at $-7$ and move $9$ units to the right instead of the left.

When subtracting a negative number, it is equivalent to adding its positive counterpart. Therefore, $-(-9)$ becomes $+9$.

So, starting at $-7$ and moving $9$ units to the right on the number line would give us the correct representation of the expression.