Math, asked by lily9tanisha, 4 months ago

2х + Зу = 7
(а - b) х + (a + b) y = За + b – 2​

Answers

Answered by amitnrw
3

Given : 2х + Зу = 7

(а - b) х + (a + b) y = За + b – 2​

To find :  Solve

Solution:

2х + Зу = 7  multiply by a + b

=> 2(a + b)x  + 3(a + b)y  = 7a  + 7b   Eq1

(а - b) х + (a + b) y = За + b – 2​    multiply by 3

=> 3(a - b)x + 3(a + b) y  = 9a + 3b - 6   Eq2

Eq2  - Eq1

=>  (a  - 5b) x   =  2a - 4b  - 6

=> x  =  (2a - 4b - 6) / (a - 5b )    

2х + Зу = 7  multiply by a-  b

=>  2(a - b)x  + 3(a - b)y  = 7a - 7b   Eq3

(а - b) х + (a + b) y = За + b – 2​    multiply by 2

=> 2(a - b)x + 2(a + b) y  = 6a + 2b - 4   Eq4  

Eq3 - Eq4

=>  ( a  - 5b)y  =  a  - 9b  + 4

=> y  = (a - 9b + 4)/(a - 5b )    

Learn More

If x²-y²= 12 and x³+y³ = 72, find the value of x and y​ - Brainly.in

brainly.in/question/8403056

Solve the simultaneous equations x+y=4 ; 2x-3y=-2 graphically ...

brainly.in/question/8383505

Answered by hukam0685
0

Step-by-step explanation:

Given:

2x + 3y = 7...eq1 \\  \\ (a - b)x + (a + b)y = 3a + b - 2 ...eq2\\  \\

To find: Value of x and y

Solution:

Method used: Substitution Method

Step 1: Write eq1 in terms of y

3y = 7 - 2x...eq3 \\

Step 2: Multiply eq 2 by 3 and substitute the value of 3y from eq3

3(a - b)x + (a + b)3y = 3(3a + b - 2 )  \\  \\ 3(a - b)x + (a + b)(7 - 2x) = 9a + 3b - 6 \\  \\ 3ax - 3bx + 7a - 2ax + 7b - 2bx = 9a + 3b - 6 \\  \\ ax - 5bx = 9a - 7a + 3b - 7b - 6 \\  \\ x(a - 5b) = 2a - 4b - 6 \\  \\ x =  \frac{2a - 4b - 6}{a - 5b}  ...eq4\\  \\

Step 3: Put value of x from eq 4 into eq1

2x + 3y = 7 \\  \\ 2 \left( \frac{2a - 4b - 6}{a - 5b}  \right) + 3y = 7 \\  \\  \frac{4a - 8b - 12 }{a - 5b}  + 3y = 7 \\  \\ 3y =  \frac{7a - 35b - 4a + 8b + 12}{a - 5b}  \\  \\ 3y =  \frac{3a - 27b + 12}{a - 5b}  \\  \\ y =  \frac{ \cancel3(a - 9b + 4)}{ \cancel3(a - 5b)}  \\  \\ y =  \frac{a - 9b + 4}{a - 5b}  \\  \\

Final answer:

Value of x and y are

\bold{\pink{ x =  \frac{2a - 4b - 6}{a - 5b}}} \\   \\\bold{\green{ y =  \frac{a - 9b + 4}{a - 5b}}} \\  \\

respectively.

Hope it helps you.

To learn more on brainly:

1) 22/x+y+15/x-y=5,55/x+y +40/x-y=13

https://brainly.in/question/42309773

2) find quadratic polynomial whose zeroes are 2/3 and -8/9

https://brainly.in/question/42746235

Similar questions