Answer:
and 
The ordered pair solutions are
,
,
, and
.
Step-by-step explanation:
I'm assuming the system is
:


























Therefore,
and 
The ordered pair solutions are
,
,
, and
.
567 = 500+60+7
4*567 = 4*(500+60*7)
4*567 = 4*500 + 4*60 + 4*7 ... see note below
4*567 = 2000 + 240 + 28
4*567 = 2268
--------
note: multiply the outer term 4 by each term inside the parenthesis to use the distributive property. The general distributive property is a*(b+c) = a*b+a*c. This can be extended to a*(b+c+d) = a*b+a*c+a*d. You can have as many terms as you like inside the parenthesis.
If 30% were perfect, 70% were not perfect. So we know that 70% of the total number of photographs is 210.
p(70/100)=210 multiply both sides by 100
70p=21000 divide both sides by 70
p=300
So there are 300 photographs in all.