Exercice 1 : Calculer les nombres relatifs (6 points) 1. (-5) + (+8) = 2. (+7) − (-4) = 3. (-12) + (-6) = 4. (+9) × (-3) = 5. (-15) + (+5) =

1. Step 1: Add the numbers. $$(-5) + (+8) = -5 + 8 = \boxed{3}$$
2. Step 1: Change subtraction of a negative to addition of a positive. $$(+7) - (-4) = 7 + 4 = \boxed{11}$$
3. Step 1: Add the negative numbers. $$(-12) + (-6) = -12 - 6 = \boxed{-18}$$
4. Step 1: Multiply the numbers. A positive times a negative is a negative. $$(+9) \times (-3) = \boxed{-27}$$
5. Step 1: Divide the numbers. A negative divided by a positive is a negative. $$(-15) \div (+5) = \boxed{-3}$$

1. Step 1: Calculate the power. $$2^3 = 2 \times 2 \times 2 = \boxed{8}$$
2. Step 1: Calculate the power. A negative number raised to an even power is positive. $$(-3)^2 = (-3) \times (-3) = \boxed{9}$$
3. Step 1: Use the rule $a^m \times a^n = a^{m+n}$. $$5^2 \times 5^3 = 5^{2+3} = 5^5$$

Given: Longueur ($L$) = 12 m, Largeur ($W$) = 8 m.

1. Calculer le périmètre du terrain.