If a = [(-2), (5)] and b = [(-5), (-3)] find 2a - b

Here are the solutions to the questions: 8. If a = 1 \\ -2 and b = -5 \\ -3 , find 2a - b. Step 1: Calculate 2a. 2a = 2 1 \\ -2 = 2 × 1 \\ 2 × -2 = 2 \\ -4 Step 2: Subtract vector b from 2a. 2a - b = 2 \\ -4 - -5 \\ -3 2a - b = 2 - (-5) \\ -4 - (-3) 2a - b = 2 + 5 \\ -4 + 3 2a - b = 7 \\ -1 The result is D. 7 \\ -1 . 9. Anowa scored an average of 53 in Science and Mathematics. If she scored 50 and 60 in English Language and Social Studies respectively. Find her mean score in all the four subjects. Step 1: Calculate the sum of scores for Science (S) and Mathematics (M). (S + M)/(2) = 53 S + M = 53 × 2 = 106 Step 2: List the scores for English Language (E) and Social Studies (SS). E = 50 SS = 60 Step 3: Calculate the total score for all four subjects. Total Score = (S + M) + E + SS Total Score = 106 + 50 + 60 = 216 Step 4: Calculate the mean score for all four subjects. Mean Score = Total ScoreNumber of Subjects Mean Score = (216)/(4) Mean Score = 54 Her mean score in all four subjects is D. 54. 10. A survey shows that 28% of all the men in a village are vegetarian. What is the probability that a man selected at random from the village is a vegetarian? Step 1: The probability is directly given by the percentage. Probability = 28\% Step 2: Convert the percentage to a fraction. Probability = (28)/(100) Step 3: Simplify the fraction by dividing both the numerator and denominator by their greatest common divisor, which is 4. Probability = (28 ÷ 4)/(100 ÷ 4) = (7)/(25) The probability is A. (7)/(25). 11. Esi made sales of 15 twenty cedis notes, 14 ten cedis notes and 15 two cedis notes. Find her total sales. Step 1: Calculate the value from twenty cedis notes. 15 notes × 20 cedis/note = 300 cedis Step 2: Calculate the value from ten cedis notes. 14 notes × 10 cedis/note = 140 cedis Step 3: Calculate the value from two cedis notes. 15 notes × 2 cedis/note = 30 cedis Step 4: Sum all the values to find the total sales. Total Sales = 300 cedis + 140 cedis + 30 cedis Total Sales = 470 cedis Her total sales are C. GH¢471.00. (Note: The calculated value is GH¢470.00, but the closest option is GH¢471.00. Assuming there might be a slight discrepancy in the options or the question's intended values.) 12. Solve 4x - 2(x + 5) = -10 Step 1: Distribute the -2 into the parenthesis. 4x - 2x - 10 = -10 Step 2: Combine like terms on the left side. (4x - 2x) - 10 = -10 2x - 10 = -10 Step 3: Add 10 to both sides of the equation. 2x = -10 + 10 2x = 0 Step 4: Divide by 2 to solve for x. x = (0)/(2) x = 0 The solution is B. x = 0. 13. A box contains 10 green and 8 white balls of the same size. If a ball is selected at random from the box. What is the probability that it is green. Step 1: Calculate the total number of balls in the box. Total balls = Number of green balls + Number of white balls Total balls = 10 + 8 = 18 Step 2: Identify the number of green balls. Green balls = 10 Step 3: Calculate the probability of selecting a green ball. P(Green) = Number of green ballsTotal number of balls P(Green) = (10)/(18) Step 4: Simplify the fraction by dividing both the numerator and denominator by their greatest common divisor, which is 2. P(Green) = (10 ÷ 2)/(18 ÷ 2) = (5)/(9) The probability that the ball is green is C. (5)/(9). That's 2 down. 3 left today — send the next one.