Question

Y squared equals 4x -55
2y plus x equals 40

Answer 1

If y = - 15 , x = 70 and if y = 7 , x = 26

Explanation:

2y + x = 40 ............1

y^2 = 4x - 55 ..........2

From equation 1, x = 40 - 2y ........3

Substitutr equation 3 into equation 2

y^2 = 4( 40 - 2y ) - 55

y^2 = (160 - 8y ) - 55

y^2 = 160 - 8y - 55

y^2 = 160 - 55 - 8y

y^2 = 105 - 8y

y^2 + 8y - 105=0

y^2 + 15y - 7y - 105 = 0

( y^2 + 15y ) - ( 7y + 105 )= 0

y (y + 15 ) - 7 (y + 15 ) = 0

(y + 15 ) (y - 7 ) = 0

y + 15 = 0 OR y - 7 = 0

y = - 15 y = 7

Substitute the value if y into equation 3

If y = - 15

x = 40 - 2( - 15 )

x = 40 + 30

x= 70

If y = 7

x = 40 - 2 ( 7 )

x = 40 - 14

x = 26