Question

143=7+8(3-7x) solve and justify

Answer 1

Justify means plug answer in and verify

so distribute 8(3-7x)=24-56x

143=7+24-56x
143=31-56x
minus 31 both sides
112=-56x
divide both sides by -56
-2=x

justify

plug it back
143=7+8(3-7x)
143=7+8(3-7(-2))
143=7+8(3-(-14))
143=7+8(3+14)
143=7+8(17)
143=7+136
143=143

true

x=-2