If y varies directly as x, and y is 180 when x is n and y is n when x is 5, what is the value of n?
18

30

Step-by-step explanation:

y varies directly with x, so:

y = kx

When x = n, y = 180.

180 = kn

When x = 5, y = n.

n = 5k

Solve for k in the first equation:

k = 180 / n

Substitute into the second equation:

n = 5 (180 / n)

n = 900 / n

n² = 900

n = 30

600,000,000,000, or 6e14

step-by-step explanation:

step by step resolutions

1) n+n+1+n+2=51

3n+3=51

3n=48

n=16

the three numbers are 16, 17 and 18.

2) x+15=4x

3x=15

x=5

radha is now 5 years old

3) the two digits are x and y.

y=3x

(10x+y)+(10y+x)=88

y=3x

11x+11y=88

y=3x

x+y=8

x+3x=8

x=2

the original number can be either 28 or 82.

4) n+(n+2)+(n+4)=48

3n+6=48

3n=42

n=14

the numbers are 14, 16 and 18.

5) y=x+3

10y+x+10x+y=143

y=x+3

11x+11y=143

y=x+3

x+y=13

x+x+3=13

2x=10

x=5

the original number can be 57 or 75.

hope this !