If 15x + 17y =21 and 17x + 15y = 11 then find the value of x + y and also x -y.
Answers
Answered by
0
Step-by-step explanation:
x+y=1
x-y=(-5)
is the answer for your question
Answered by
0
Answer:
x + y = 1
x - y = -5
Step-by-step explanation:
1) 15x + 17y = 21
⇒ 15x = 21 - 17y
⇒ x = (21 -17y) / 15
2) 17x + 15y = 11
⇒ 17 * (21 - 17y / 15) + 15y = 11
⇒
⇒ 357 - 289y + 225y = 165
⇒ 357 - 165 = 289y - 225y
⇒ 192 = 64y
⇒ 192/64 = y
⇒ 3 = y
⇒ x = (21 - 17y) / 15
⇒ x = (21 - 17*3) / 15
⇒ x = (21 - 51) / 15
⇒ x = -30 / 15
⇒ x = -2
x + y = (- 2) + 3 = 1
x - y = (- 2) - (3) = -2 - 3 = -5
Similar questions