Bilangan Bulat (Kls.7)

Explanation
The given expression (-3 x (-18)) + (-3 x 13) represents the distributive property. According to this property, when a number is multiplied by the sum of two numbers, it is equivalent to multiplying the number individually by each number in the sum and then adding the products together. In this case, -3 is being multiplied by the sum (-18 + 13). Therefore, we can distribute -3 to both numbers in the sum: (-3 x -18) + (-3 x 13). This simplifies to 54 + (-39), which equals 15.

Explanation
The expression 3 + (-6) - 7 can be simplified by first adding 3 and -6, which gives -3. Then, subtracting 7 from -3 gives -10. Therefore, the correct answer is -10.

Explanation
The given expression (-3) + 6 x 2 can be simplified using the order of operations, which states that multiplication should be done before addition. Thus, we first multiply 6 and 2, which gives us 12. Then, we add -3 to 12, resulting in a final value of 9.

Explanation
The expression 2 x (-5) - 4 : 2 can be simplified by following the order of operations, which states that multiplication and division should be done before addition and subtraction. First, we perform the multiplication, which gives us -10. Then, we perform the division, which gives us -5. Finally, we subtract 4 from -5, resulting in -9. Therefore, the correct answer is -12.

Explanation
The given statement states that a code indicating "-30" means 30 meters towards the east. Therefore, if the code is "8", it would mean 8 meters towards the west.

Explanation
The expression (-7) + 8 - 6 - (-4) can be simplified by first removing the parentheses. The negative sign in front of (-4) can be rewritten as a positive sign, resulting in (-7) + 8 - 6 + 4. Then, we can combine like terms by adding and subtracting from left to right. Starting with (-7) + 8, we get 1. Then, subtracting 6 from 1 gives us -5. Finally, adding 4 to -5 gives us -1. Therefore, the correct answer is -1.

Explanation
The expression 6 + (-4) - (-9) - 5 can be simplified by first adding the positive and negative numbers separately. The sum of 6 and -4 is 2. Then, the subtraction of -9 becomes an addition of 9, resulting in 11. Finally, subtracting 5 from 11 gives us 6. Therefore, the correct answer is 6.

Explanation
The given expression involves multiplication and addition/subtraction. According to the order of operations, we perform the multiplication first. 5 multiplied by -4 equals -20. Then we add -4 to -20, which gives us -24. Finally, we subtract 6 from -24, resulting in -30. Therefore, the correct answer is -30.

Explanation
The given expression involves multiplication and addition/subtraction. According to the order of operations (PEMDAS/BODMAS), multiplication is performed before addition/subtraction. So, we first multiply 2 and -3, which gives us -6. Then, we add -5 and -6, which gives us -11. Finally, we subtract 7 from -11, resulting in -18. Therefore, the correct answer is -18.

Explanation
The given expression involves subtraction, division, and addition. According to the order of operations, we need to perform the division first. When we divide -8 by -2, we get 4. Then, we subtract 4 from 4, which gives us 0. Finally, we add 0 to 5, resulting in 5. Therefore, the correct answer is 5.