7. Solve [tex]-4(6x + 3) = -12(x + 10)[/tex].

A. [tex]x = -5[/tex]
B. [tex]x = 9[/tex]
C. [tex]x = 2[/tex]
D. [tex]x = 5[/tex]



Answer :

To solve the equation [tex]\(-4(6x + 3) = -12(x + 10)\)[/tex] step-by-step, we need to follow the process of distributing, simplifying, and isolating the variable [tex]\(x\)[/tex]. Here is the detailed solution:

1. Distribute the constants on both sides of the equation:

On the left side, distribute [tex]\(-4\)[/tex] over the terms inside the parentheses:
[tex]\[ -4(6x + 3) = -4 \cdot 6x + (-4) \cdot 3 = -24x - 12 \][/tex]

On the right side, distribute [tex]\(-12\)[/tex] over the terms inside the parentheses:
[tex]\[ -12(x + 10) = -12 \cdot x + (-12) \cdot 10 = -12x - 120 \][/tex]

2. Rewrite the equation with the distributed terms:

[tex]\[ -24x - 12 = -12x - 120 \][/tex]

3. Move all terms involving [tex]\(x\)[/tex] to one side of the equation:

To do this, add [tex]\(24x\)[/tex] to both sides of the equation to move the [tex]\(x\)[/tex] terms together:
[tex]\[ -24x + 24x - 12 = -12x + 24x - 120 \][/tex]
Simplifying gives:
[tex]\[ -12 = 12x - 120 \][/tex]

4. Move the constant terms to the other side of the equation:

Add 120 to both sides of the equation to isolate the term involving [tex]\(x\)[/tex]:
[tex]\[ -12 + 120 = 12x - 120 + 120 \][/tex]
Simplifying gives:
[tex]\[ 108 = 12x \][/tex]

5. Solve for [tex]\(x\)[/tex] by dividing both sides by 12:

[tex]\[ \frac{108}{12} = \frac{12x}{12} \][/tex]
Simplifying gives:
[tex]\[ 9 = x \][/tex]

So, the solution to the equation [tex]\(-4(6x + 3) = -12(x + 10)\)[/tex] is [tex]\(x = 9\)[/tex].

Therefore, the correct answer is:
[tex]\[ \boxed{9} \][/tex]