Question

find value of 3x+2y=25 and 2x-y=10 by substitution method​

Answer 1

Step-by-step explanation:

3x+2y=25 -----(1)

2x-y =10 ---(2)

x=10+y/2 -----[from equation (2)]

now put value of x in equation (1)

3 (10+y/2)+2y=25

(30+3y/2)+2y=25

now take lcm in above

(30+3y+2y)/2=25

30+3y+2y= 50

30+5y=50

5y=50-30

5y=20

y=4

Therefore y will be 4

if y is 4 then x will be

2x-y=10

2x-4=10

2x=14

x=7

Therefore x will be 7

Answer 2

Answer:

x = 45/7

20 = y

Step-by-step explanation:

3x+2y=25 ----(1)

2x-y=10 ----(2)

2x-10=y ---- from (1)

Substituting y in (1)

3x + 2(2x-10) = 25

3x + 4x - 20 = 25

7x = 20+25

7x = 45

x = 45/7

Substituting x in (2)

2x-y=10

2(45/7) - y = 10

90/7 - y = 10

90 - y = 10 × 7

90 - y = 70

90 - 70 = y

20 = y