Question

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

Answer 1

Step-by-step explanation:

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

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

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

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

$12-9-x=10$

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

$-x+3=10$

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

$-x+3-3=10-3$

$Simplify$

$-x=7$

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

$\frac{-x}{-1}=\frac{7}{-1}$

$Simplify$

$x=-7$

Answer 2

Answer:

-7

Step-by-step 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