Solve the following pair of equations.

4(x + 2) + 5(y + 2) = 20 and 5x + 4y = 7

Given,

4(x + 2) + 5(y + 2) = 20

⇒ 4x + 8 + 5y + 10 = 20

⇒4x + 5y = 2        ....(1)
5x + 4y = 7            ....(2)
On adding (1) and (2), we get
9x + 9y = 9
x + y = 1               ....(3)
On subtracting (1) from (2), we get
x − y = 5              ....(4)
On adding (3) and (4), we get
2x = 6
x = 3
By putting x = 3 in (3), we get
3 + y = 1
y = −2

Hence, the value of x and y are 3 and −2