Question

Solve the simultaneous equations
4x+y=20
x-y=15

Answer 1

Step-by-step explanation:

add the both equations

then find x

substitute x value in equation 1

Answer 2

Answer:

The given equations are;

4x + y = 20 . . . . (1)

x - y = 15 . . . . . . (2)

Now,

Adding equations (1) and (2), we get

4x + y + x - y = 20 + 15

4x + x + y - y = 35

5x = 35

x = 35/5

x = 7

Putting the value of x = 7 in equation (1) we get,

4x + y = 20

➞ 4(7) + y = 20

➞ 28 + y = 20

➞ y = 20 - 28

➞ y = - 8

∴ The value of x = 7, y = - 8 is the solution of the system of the given equations.