Question

3x + 4y=60 , 5x - 2y=70​

Answer 1

Answer:

Solution :-

◘ 3x + 4y = 60 and 5x - 2y = 70 by elimination method.

3x + 4y = 60 . . . . . (1)

5x - 2y = 70 . . . . . (2)

❖ Multiply equation (1) by 5 (2) by 3, we get

15x + 20y = 300 . . . . . (3)

15x - 6y = 210 . . . . . . (4)

❈ Adding (3) and (4) we get,

15x + 20y = 300

15x - 6y = 210

(-) (+) (-)

__________________

26y = 90

y = 90/26

y = 45/13

✭ Substituting the value of y = 45/13 in equation (1) we get,

★ 3x + 4y = 60

➞ 3x + 4(45/13) = 60

➞ 3x + 180/13 = 60

➞ 3x = 60 - 180/13

➞ 3x = 780 - 180/13

➞ 3x = 600/13

➞ x = 600/13 × 1/3

➞ x = 200/13

∴ The value of x = 200/13, y = 45/13 is the solution of the system of the given equations.