contestada

What belongs in the box marked with the question mark in the proof?
Given: 3x - 4 = 2(x + 8), Prove: x = 20
Statement

Reason

(1) 3x - 4 = 2(x + 8)



(2) 3x - 4 = 2x + 16



(3) 3x = 2x + 20                                               (?)



(4) x = 20

Respuesta :

choixongdong
(1) 3x - 4 = 2(x + 8) ..............Given
(2) 3x - 4 = 2x + 16...............Distributive property
(3) 3x = 2x + 20-----------------Addition property of equality
(4) x = 20-------------------------Subtraction property of equality

Answer:

Subtraction

[tex]3\cdot(x)-2\cdot(x)=20[/tex]

Step-by-step explanation:

We can determine x=20 by solving x:

[tex]3\cdot(x)-4=2\cdot(x+8)[/tex]

we multiply the terms in the brackets with 2:

[tex]3\cdot(x)-4=2\cdot(x)+2\cdot(8)[/tex]

We then take the 2x to the right hand side

[tex]3\cdot(x)-3\cdot(x)=20[/tex]

[tex]x=20[/tex]