Question

Solve for x:
3*4+-9-x=10

Answer 1

Explanation:

`3\cdot \:4+\left(-9\right)-x=10`

`\mathrm{Remove\:parentheses}:\quad \left(-a\right)=-a`

`3\cdot \:4-9-x=10`

`\mathrm{Multiply\:the\:numbers:}\:3\cdot \:4=12`

`12-9-x=10`

`\mathrm{Subtract\:the\:numbers:}\:12-9=3`

`-x+3=10`

`\mathrm{Subtract\:}3\mathrm{\:from\:both\:sides}`

`-x+3-3=10-3`

`Simplify`

`-x=7`

`\mathrm{Divide\:both\:sides\:by\:}-1`

`(-x)/(-1)=(7)/(-1)`

`Simplify`

`x=-7`

Answer 2

-7

Explanation:

first multiply 3 and 4 because PEMDAS

so it now looks like

12 - 9 - x = 10

now minus 12 and 9

3 - x = 10

move x to the other side by adding x to both sides

3 = 10 + x

and move 10 to the other side by subtracting 10 to both sides

3 - 10 = x

x = -7

now check

3*4 - 9 - (-7) = 10 ?

12 - 9 + 7 = 10 ?

3 + 7 = 10 ?

10 = 10