x = second number
4x - 7 = first number ← the first is 7 less than 4 times the second

6x = 2(4x - 7) + 2 ← six times second is two more than twice first
6x = 8x - 14 + 2 ← distributive property
6x = 8x - 12 ← combined like terms
-2x = -12 ← subtracted 8x from each side
x = 6 ← divided each side by -2
4x - 7 = 17 ← substituted 6 for x into first number description