  ### Home > CC4 > Chapter 1 > Lesson 1.1.1 > Problem1-9

1-9.

Simplify each expression. Homework Help ✎

1. $−42+(−17)$

Because both numbers are negative, you can add them. Don't forget to make the answer negative.

$−59$

1. $8−(−9)$

Subtracting a negative is the same as adding a positive. Think of this as $8+9$.

1. $8(−9)$

Because there is only one negative number, the final answer will be negative. Multiply the numbers.

$−72$

1. $−42\div(−7)$

The rules for division are the same as the rules for multiplication.

1. $−2(−3)(−4)$

Multiplying two negatives makes a positive.

$−2(−3)=6$       So
$−2(−3)(−4)=6(−4)$

Multiplying a positive and a negative makes a negative.

$6(−4)=−24$

$−24$

1. $−18−7$

Subtraction is like adding a negative. Refer to part (a) to see the process.

1. $(−5)^2$

Because the exponent is outside the parentheses, think of this as $(−5)(−5)$.

$25$

1. $−5^2$

Think of this as $−(5^2)$
which is $−(5)(5)$.

1. $\sqrt { 49 }$

What positive number multiplied by itself is $49$?

$7$