This is a system of equations. You can solve it by substitution or elimination. I'm going to use substitution x - 2y = -4.5; add 2y to each side x - 2y + 2y = -4.5 + 2y; simplify x = 2y - 4.5 2(2y - 4.5) + 3y = 12 4y - 9 + 3y = 12 7y - 9 = 12 7y - 9 + 9 = 12 + 9 7y = 21 y = 3 <--------first answer x - 2y = -4.5 x - 2(3) = -4.5 x - 6 = -4.5 x -6 + 6 = -4.5 + 6 x = 1.5 <--------second answer Check: 2(1.5) + 3(3) = 12? 3 + 9 = 12? 12 = 12; It checks 1.5 - 2(3) = -4.5? 1.5 - 6 = -4.5? -4.5 = -4.5; It checks x = 1.5 and y = 3 <-----------Final Answer
8/15 or somthing like that it you might be souposed to solve it diferent than i did
Answer:
26
Step-by-step explanation:
Answer:
37.5 miles per hour
Step-by-step explanation:
The traffic along a stretch road moves at an average speed that carried inversely as the number of cars
Average speed= k/number of cars.
When there are 1,500 cars the average speed is 45
The first step is to calculate the constant k
45= k/1500
k = 1,500 × 45
k= 67,500
Therefore the average speed when there are 1,800 cars can be calculated as follows
Average speed= 67,500/1,800
= 37.5 miles per hour
Hence the average speed is 37.5 moles per hour
