Question

If 2a +1:21:: 4: 7 then​

Answer 1

Answer:

11/3

Step-by-step explanation:

2a+1/21 = 4/7

(2a+1)*7 = 4*21

2a+1 = 12

a = 11/3

Answer 2

Step-by-step explanation:

$\tt \longmapsto \:2a + 1 :21::4:7 \\ \\ \tt \longmapsto \:2a + 1 :21 = 4:7 \\ \\ \tt \longmapsto \frac{2a + 1}{21} = \frac{4}{7} \\ \\ \tt \longmapsto 7(2a + 1) = 4 \times 21 \\ \\ \tt \longmapsto 14a + 7 = 84\\ \\ \tt \longmapsto 14a = 84 - 7 \\ \\ \tt \longmapsto 14a = 77 \\ \\ \tt \longmapsto a = \frac{77}{14} \\ \\ \tt \longmapsto a=\dfrac{11}{2}\\ \\ \tt \longmapsto a=5.5$