Question

Solve for x.
9x+ 28 = 5 (x+ 8)
Simplify your answer as much as possible.

Answer 1

`\tt Step-by-step~explanation:`

When we solve for x, we have to move all the numbers that do not contain the variable on one side, and keep x on the other side. In other words, we have to isolate the variable.

`\tt Step~1:`

Equation: 9x + 28 = 5 (x + 8)

Using PEMDAS*, we will distribute the 5 to x + 8.

`\tt 5(x+8)\\5x+40\\9x+28=5x+40`

`\tt Step~2:`

Then, let's subtract 28 from the left side of the equation to cancel the 28, then do the same thing on the right side.

`\tt 9x+28(-28)^(**)=5x+40(-28)^(**)\\9x=5x+12`

`\tt Step~3:`

Subtract 5x from both sides to bring it to the left side of the equation.

`\tt 9x(-5x)=5x(-5x)+12\\4x=12`

`\tt Step~4:`

Finally, we can divide both sides by 4 to get x by itself.

`\tt (4x)/(4) =x\\(12)/(4)=3\\ x=3`

`\large\boxed{\tt Our~final~answer:~x=3}`

*PEMDAS + Parentheses first, then Exponents, then Multiplication/Division, and finally Addition/Subtraction.

**The numbers in parentheses here tell you to ADD/SUBTRACT, not multiply.

Answer 2

9x+ 28 = 5 (x+ 8)

9x+28 = 5x+40 (use distribution property)

4x+28 = 40 (subtract 5x when bringing to the other side)

4x = 40-28 (subtract 28 when bringing to the other side)

4x = 12

x = 12/4 (divide)

x = 3