If ur smart u should know this 10 points

They're all simple.

150 = 25r

The r is multiplied for 25, so we should know what r equals to when it's not multiplied (1r).

So divide both terms for 25.

150/25 = 25r/25

6 = r

r = 6 <- answer

38 = 4p

Same thing here (divide both terms for 4)

38/4 = 4p/4

38/4 = p

p = 38/4 and simplify p = 19/2 <- answer

18 = a/20

We have a fraction, and we have to "delete" it.

There are two ways.

First one: multiply both terms for the denominator of the fraction.

18*20 = a/20 * 20

360 = a

a = 360 <- answer

Second way.

Take the two fractions to the common denominator (20) and do the LCM.

360/20 = a/20. Multiply both for 20

360 = a

a = 360

0 = 10x

0/10 = 10x/10

x = 0 <- answer