the square of the sum of a number and 2 is equal to the sum of the number and 4. What is the number?​

Sagot :

Answer:

[tex] [/tex]

x = 0 and 3

Step-by-step explanation:

let x = be the number

[tex](x + 2) {}^{2} = x + 4[/tex]

[tex]x {}^{2} + 4x + 4 = x + 4[/tex]

[tex]x {}^{2} + 4x + 4 - x - 4 = 0[/tex]

combine similar terms

[tex]x {}^{2} + 3x = 0[/tex]

[tex]x(x + 3) = 0[/tex]

[tex]x = 0[/tex]

[tex]x + 3 = 0[/tex]

[tex]x = 0 - 3[/tex]

[tex]x = - 3[/tex]

Therefore x = 0 and 3

CHECKING:

x = 0

[tex](x + 2) {}^{2} = x + 4[/tex]

[tex](0 + 2) {}^{2} = 0 + 4[/tex]

[tex]2 {}^{2} = 4[/tex]

[tex]4 = 4[/tex]

x = 3

[tex](x + 2) {}^{2} = x + 4[/tex]

[tex]( - 3 + 2) {}^{2} = - 3 + 4[/tex]

[tex]( - 1) {}^{2} = 1[/tex]

[tex]1 = 1[/tex]