21=3xv what is the number for v

Step-by-step explanation:

1 Divide both sides by 33.

\frac{21}{3}=xv

3

21

=xv

2 Simplify \frac{21}{3}

3

21

to 77.

7=xv

7=xv

3 Divide both sides by vv.

\frac{7}{v}=x

v

7

=x

4 Switch sides.

x=\frac{7}{v}

x=

v

7

Done

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.