Question

if a+b=60 ,a-b=40 and a=22 then find b ?

Answer 1

since,
a+b=60
22+b=60
b=60-22
b=38
a-b=40
22-b=40
b=-1(40-22)
b=-18

Answer 2

Thank you for asking this question. Here is your answer:

| a+b| = 60

| a+b|² = 3600

(a+b) . (a+b) = 3600

|a|² + |b|²  + 2 a.b = 3600 -- (1)

| a-b| = 40

|a-b|² = 1600

(a-b) . (a-b) = 1600

|a|² + |b|²  - 2 a.b  = 1600

(1) and (2)

|a|² + |b|²  + 2 a.b + |a|² + |b|²  + 2 a.b = 3600 + 1600

2(|a|² + |b|²) = 5200

|a|² + |b|² = 2600

|b|² = 2600 - 484

|b|² = 2116

|b|² = 46 is the final answer.

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