Question

solve using the multiplication principle. dont forget to perform a check.
$-dfrac{1}{8}x = -dfrac{9}{10}$

Explanation:

Step1: Isolate x via reciprocal multiply

Multiply both sides by $-8$:
$$-\frac{1}{8}x \times (-8) = -\frac{9}{10} \times (-8)$$

Step2: Simplify to solve for x

Calculate the right-hand side:
$$x = \frac{72}{10} = \frac{36}{5}$$

Step3: Check solution in original equation

Substitute $x=\frac{36}{5}$ into $-\frac{1}{8}x$:
$$-\frac{1}{8} \times \frac{36}{5} = -\frac{36}{40} = -\frac{9}{10}$$
This matches the right-hand side of the original equation.

Answer:

$x=\frac{36}{5}$ (or $7.2$)