given that for all numbers of p and q,
q = 5/3p + 46
lets find p when q is 21
so lets substitute the value of q into the given equation
q = 5/3p + 46
21 = 5/3p + 46
lets collect like terms
21 - 46 = 5/3p
-25 = 5/3p
lets cross multiply
3 X -25 = 5p
-75 = 5p
5p = -75
divide both sides by 5
5p/5 = -75/5
p = -15
therefore for all values of p and q, q = 5/3p + 46,
the value of p is -15 when q is 21
