Question

use your value of x to find AB and BC
x=5
AB=3x+1
BC=4x-5

Answer 1

ok so substitute

if x is equal to 5
and
AB is equal to 3 times x plus 1

that would mean

AB is equal to 3 times 5 plus 1

so AB is equal to?

Answer 2

x = 5
\[AB=3x+1\]
\[AB=3(5)+1\]
\[AB=15+1\]
\[AB=16\]

--------------------------------------------------

\[BC=4x-5\]
\[BC=4(5)-5\]
\[BC=20-5\]
\[BC=15\]