Question

1. distance

solve for r. ( d = rt )

1. simple interest

solve for t: ( i = prt )

1. area of a rectangle

solve for w: ( a = lw )

1. perimeter of an equilateral triangle

solve for s: ( p = 3s )

1. area of a trapezoid

solve for h: ( a = \frac{h}{2}(b_1 + b_2) )

Explanation:

Problem 20: Solve for \( r \) in \( d = rt \)

Step 1: Isolate \( r \)

To solve for \( r \), we divide both sides of the equation \( d = rt \) by \( t \) (assuming \( t
eq 0 \)).
\[
\frac{d}{t} = \frac{rt}{t}
\]

Step 2: Simplify

Simplifying the right - hand side, \( t \) in the numerator and denominator cancels out.
\[
r=\frac{d}{t}
\]

Step 1: Isolate \( t \)

Divide both sides of the equation \( I = Prt \) by \( Pr \) (assuming \( Pr
eq0 \)).
\[
\frac{I}{Pr}=\frac{Prt}{Pr}
\]

Step 2: Simplify

Simplifying the right - hand side, \( Pr \) in the numerator and denominator cancels out.
\[
t = \frac{I}{Pr}
\]

Step 1: Isolate \( w \)

Divide both sides of the equation \( A=lw \) by \( l \) (assuming \( l
eq0 \)).
\[
\frac{A}{l}=\frac{lw}{l}
\]

Step 2: Simplify

Simplifying the right - hand side, \( l \) in the numerator and denominator cancels out.
\[
w=\frac{A}{l}
\]

Answer:

\( r = \frac{d}{t} \)

Problem 22: Solve for \( t \) in \( I=Prt \)