so 4(x+5)=x+8
first we distribute
using the distributive property of multiplication which is a(b+c)=(ab)+(ac)
4(x+5) is also (4x)+(4(5))=4x+20
4x+20=x+8
subtract x from both sides
3x+20=8
subtract 20 from both sides
3x=-12
divide both sides by 3
x=-4