Question

1. Show that the equation 2x + 7 =17 and 2x/5 + 15 = 17 have the same root
2. if 3/4th of a number is 15, find 4/5th of the number

Answer 1

2. Let the number be x
By question, 3/4x=15
3x=15*4
3x=60
x=60/3
x=20
Therefore ,4/5*20=16

Answer 2

Answer:

1) given equation has equal root.

2) 4/5 of a number = 16

Step-by-step explanation:

1) 2 x + 7 =17

2 x = 17 - 7 = 10

x = 10/2 = 5.........i

2 x/5 + 15 = 17

2 x/5 = 17 - 15

2 x/5 = 2

2 x = 2 * 5

x = 10/2 = 5................ii

from i and ii it is clear that both the given equation has equal root.

2)

Let the number be x

3/4 of x = 15

x = 15 * 4/3 = 60/3 = 20

4/5 of the number = 4/5 * 20 = 4 * 4 = 16