Solving for an Unknown - ISEE Middle Level: Mathematics Achievement

$x = 5$. Add 11 to both sides, then divide by 4 to isolate $x$.

$x = 6$. Subtract 2 from both sides, then divide by 3 to isolate $x$.

$x = 7$. Divide both sides by 3, then add 2 to isolate $x$.

$x = 7$. Subtract $x$ from both sides, then subtract 5 to isolate $x$.

$x = 4$. Subtract $2x$ from both sides, then add 4 to isolate $x$ and divide by 4.

$x = 15$. Multiply both sides by $\frac{3}{2}$ to isolate $x$.

$x = 10$. Subtract 1 from both sides, then divide by 0.2 to isolate $x$.

$x = 16$. Multiply both sides by $\frac{4}{3}$ to isolate $x$.

$x = 13$. Multiply both sides by 4, then add 1 to isolate $x$.

$x = 16$. Divide both sides by 0.5, or multiply by 2, to isolate $x$.

$x = 4$. Divide both sides by 2, then subtract 3 to isolate $x$.

$x = 3$. Subtract 7 from both sides, then divide by -2 to isolate $x$.

Multiplication Property of Equality. This property preserves equality when both sides are multiplied by the same nonzero number, enabling isolation of variables.

Dividing by $a$ (for $a \ne 0$). To reverse multiplication and solve for the variable, perform division by $a$ on both sides, provided $a \ne 0$.

$x = 12$. Subtract 7 from both sides to isolate $x$, using the subtraction property of equality.

$x = 24$. Multiply both sides by 6 to isolate $x$, applying the multiplication property of equality.

$x = 5$. Add 9 to both sides to isolate $x$, applying the addition property of equality.

$x = 9$. Divide both sides by 5 to isolate $x$, using the division property of equality.

Subtracting $a$. To undo addition and isolate the variable, apply the inverse by subtracting $a$ from both sides of the equation.

Isolate the variable to find its value. Solving equations requires performing inverse operations to express the variable alone on one side, revealing its value that satisfies the equation.

$x = 4$. Add 1 to both sides, then multiply by $\frac{2}{5}$ to isolate $x$.

$x = 20$. Add 3 to both sides, then multiply by 5 to isolate $x$.