Answer:
2. i) Positive
ii) Same sign as the original number
3. 80
Explanation:
2. i) The sign of a number multiplied by itself an even number of times is always positive
Therefore, given that 8 is an even number, the sign of the product is negative
ii) The sign of a negative number multiplied by itself an odd number of times is always negative, while the sign of a negative number multiplied by itself an even number of times is always positive
Given that 99 is an odd number, if the number being multiplied by itself 99 times is negative, the product is negative
However, if the number being multiplied by itself 99 times is positive, the product is positive
Therefore, the product has the same sign as the number
3. The amount gained from the sale of each facemask, x = 3
The amount the shop owner loses on selling each sanitizer, y = 2
The number of mask she sells in a particular week = 50 masks
The amount of lost in the week = 10
The total gain or loss = The amount gained from the sale of facemask - The amount she loses from the sale of sanitizer
The amount gained from the face mask sales, A = 50 × 3 = 150
The total amount gained or lost = -10 = 10 lost
∴ -10 = 150 - The amount she loses from the sale of sanitizer
The amount she loses from the sale of sanitizer, Ts = 150 + 10 = 160
The number of sanitizers she sells, n = Ts/y
∴ n = 160/2 = 80
The number of sanitizers she sells = 80