Solve 21=-4(x-3)

$$21=-4(x-3)$$

Solve for x

$$x = -\frac{9}{4} = -2\frac{1}{4} = -2.25$$

Steps for Solving Linear Equation

Divide both sides by -4.

$$-\frac{21}{4}=x-3$$

Swap sides so that all variable terms are on the left hand side.

$$x-3=-\frac{21}{4}$$

Add 3 to both sides.

$$x=-\frac{21}{4}+3$$

Convert 3 to fraction \frac{12}{4}.

$$x=-\frac{21}{4}+\frac{12}{4}$$

Since -\frac{21}{4} and \frac{12}{4} have the same denominator, add them by adding their numerators.

$$x=\frac{-21+12}{4}$$

Add -21 and 12 to get -9.

$$x=-\frac{9}{4}$$