Please HURRY!
The difference of two numbers is 8. If the sum of the smaller number and the square of the larger number is 148, what is the smaller number?

Respuesta :

Answer: The smaller number is -21 or 4

Step-by-step explanation:

Let the smaller number be y and the larger number be x , then

x - y = 8 ..................... equation 1

From the second statement

[tex]x^{2} +y = 148[/tex] .................... equation 2

combining the two equations:

[tex]x - y = 8[/tex] .......................equation 1

[tex]x^{2} + y = 148[/tex]  .................... equation 2

solving the system of equation by substitution method , from equation 1 , make y the subject of the formula.

[tex]y = x - 8[/tex] ...................... equation 3

substitute equation 3 into equation 2 , we have

[tex]x^{2} +x - 8 = 148[/tex]

[tex]x^{2} +x - 8 - 148 = 0[/tex]

[tex]x^{2} +x-156=0[/tex]

Factorizing the quadratic expression , we have

[tex](x+13)(x-12) = 0[/tex]

That is

[tex]x =- 13[/tex] or [tex]x= 12[/tex]

When  [tex]x = -13[/tex] , [tex]y = -13 - 8[/tex]

[tex]y = -21[/tex]                    (-13 , -21 )

when [tex]x = 12[/tex] , [tex]y = 12 - 8[/tex]

[tex]y = 4[/tex]                       ( 12 ,4 )

Check:

-13 - (-21)

-13 + 21 = 8

[tex](-13)^{2} -21 = 148[/tex]

Also

12 - 4 = 8

[tex]12^{2} + 4 = 148[/tex]

Therefore , the smaller number is -21 or 4

The numbers are 12 and 4. If you subtract 4 from 12, you will get 8. If you add 4 to the squared 12, which is 144, you will get 148. That means the smaller number is 4.