Question 218470
1/6(y+42)-15=-3
y/6+42/6-15=3
y/6+7-15=3
y/6=3-7+15
y/6=11
y=66 ans.
Proof:
1/6(66+42)-15=3
1/6*108-15=3
108/6-15=3
18-15=3
3=3
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4p+5-7p=-1 before changing signs try to combine like terms.
4p-7p+5=-1 
-3p+5=-1 now subtract 5 from both sides
-3p+5-5=-1-5
-3p=-6 divide both sides by -3
-3p/-3=-6/-3
p=2 ans.
Proof:
4*2+5-7*2=-1
8+5-14=-1
13-14=-1
-1=-1