is this the correct answer? I might post more on this exact post, so please bare with me? These are proportions

Question

1.) 2:5 = 4:y Answer: y=2

Answer 1

2.) 3:10 = b + 7:20

My answer: 7.14

Answer 2

3.) 5t:9 = 1:2

My answer: t=0.9

Answer 3

3.*) 2:3 = 6:q+-4

My answer: q=-5

Answer 4

4.) 3:k = 45:18

My answer: k=1.2

Answer 5

5.) 9:2 = 5:x+1

My answer: 1=x

Answer 6

6.)38:19 = n+-5

My answer: 54.29=1n

Answer 7

I think your answers to 1, 2, 5 and 6 are wrong. The other three are correct.

Here's how I did 1.

2:5 = 4:y
2y = 20
y = 10

Answer 8

1. 2/5 = 4/y,
Cross multiply:
2y = 20,
y = 10.

2. 3/10 = (b+7)/20,
Cross multiply:
10(b+7) = 60,
b + 7 = 6,
b = 6 -7 = -1.

3. 5t/9 = 1/2,
10t = 9,
t = 0.9.

4. 3/k = 45/18,
45k = 54,
k = 54/45 = 6/5.

5. 9/2 = 5/(x+1),
9(x+1) = 10,
x + 1 = 10/9,
X = 10/9 -1 = 10/9 -9/9 = 1/9.

6. 38/19 = n + (-5),
2 = n - 5,
n = 2 + 5 = 7.