Question

solve for u.

$-28 = -\frac{4}{7}u$

simplify your answer as much as possible.

$u = \square$

Explanation:

Step1: Multiply both sides by -7/4

To isolate \( u \), we multiply both sides of the equation \(-28 = -\frac{4}{7}u\) by the reciprocal of \(-\frac{4}{7}\), which is \(-\frac{7}{4}\). So we have:
\(-28 \times (-\frac{7}{4}) = -\frac{4}{7}u \times (-\frac{7}{4})\)

Step2: Simplify both sides

First, simplify the left - hand side: \(-28\times(-\frac{7}{4})=\frac{28\times7}{4}\). We can divide 28 by 4 first, \(28\div4 = 7\), then \(7\times7=49\).
On the right - hand side, \(-\frac{4}{7}u\times(-\frac{7}{4}) = u\) (because the \(-\frac{4}{7}\) and \(-\frac{7}{4}\) are reciprocals and multiply to 1, and \(1\times u=u\)).

Answer:

\(u = 49\)