Question

4x+y=17;X+4y=-7 by elimination method please solve with explanation ​

Answer 1

Answer:

x = 5 and y = -3

Step-by-step explanation:

Elimination is also substitution where we need to substitute one equation in the other equation

4x + y = 17

⇒ y = 17 - 4x → equation 1

x + 4y = -7 → equation 2

substitute equation 1 in equation 2

equation 2 will become → x + 4 ( 17 - 4x) = -7

⇒ x + 68 - 16 x = - 7

⇒ - 15x + 68 = -7

⇒ 68 + 7 = 15 x

⇒ 75 = 15 x

⇒ 75 / 15 = x

⇒ x = 5

substituting x = 5 in equation 1

y = 17 - 4x

⇒ y = 17 - 4(5)

⇒ y = 17 - 20

⇒ y = -3

Answer 2

→→ 4x+y = 17 - eq1

→→ x+4y = -7 - eq2

(4x+y)×4 = 17×4

→→ 16x+4y = 68 - eq3

now eq3-eq2

→→(16x+4y = 68)-(x+4y = -7)

→→15x = 75

→→x = 5

by putting the value in equation 1

(4×5)+y = 17

→→20+y = 17

→→ y = -3

so value of x is 5 and y is -3