Answer: How to check in explanation plus answer! (x=-6)
Explanation:
Simplifying
21 + -4x = 45
Solving
21 + -4x = 45
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-21' to each side of the equation.
21 + -21 + -4x = 45 + -21
Combine like terms: 21 + -21 = 0
0 + -4x = 45 + -21
-4x = 45 + -21
Combine like terms: 45 + -21 = 24
-4x = 24
Divide each side by '-4'.
x = -6
Simplifying
x = -6
CHECKING!
Rearrange variables to the left side of the equation: -4x=45-21
Calculate the sum or difference: -4x=24
Divide both sides of the equation by the coefficient of the variable: x=-24/4
Cross out the common factor: x=-6