Question

I need help with number 4

Answer 1

x = 9, AR = 25 , AM = 40

Explanation:

Since AM = AR + RM and AM also = 7x-23

7x - 23 = (2x + 7) + 15

7x - 23 = 2x + 22

+23 +23

7x = 2x + 45

-2x -2x

5x = 45

x = 9

Now plug x = 9 into 2x + 7 to find AR

AR = 2x + 7

= 2 (9) + 7

= 18 + 7

AR = 25

Now to find AM plug x = 9 into 7x - 23

AM = 7x - 23

= 7 (9) - 23

= 63 - 23

AM = 40

To double check, we already know that RM = 15, so add AR + RM to find AM

AM = 25 + 15

AM = 40

Answer 2

9 = x

AR = 25

AM = 40

Explanation:

AR + RM = AM

2x+7 +15 = 7x - 23

Combine like terms

2x+22 = 7x -23

Subtract 2x from each side

2x+22 -2x = 7x-2x -23

22 = 5x - 23

Add 23 to each side

22+23 = 5x-23+23

45 = 5x

Divide each side by 5

45/5 = 5x/5

9 = x

AR = 2x+7 = 2*9 +7 = 18+7 = 25

AM = 7x-23 = 7*9 -23 = 63-23 = 40