Answer:
Option A, 70
Step-by-step explanation:
Step 1: Find the Science grade
(95 + 85 + 90 + 80 + x) / 5 = 84
Step 2: Multiply both sides by 5
(95 + 85 + 90 + 80 + x) / 5 * 5 = 84 * 5
95 + 85 + 90 + 80 + x = 420
Step 3: Combine all of the numbers
95 + 85 + 90 + 80 + x = 420
350 + x = 420
Step 4: Subtract 350 from both sides
350 + x - 350 = 420 - 350
x = 70
Answer: Option A, 70
