let b = 4
const d = 5
b = d * 2 // b === 10
console.log(b)
b += d // b = b + d; b === 15
console.log(b)
b -= 2 // b = b - 2; b === 13
console.log(b)
b *= 3 // b = b * 3; b === 39
console.log(b)
b /= 3 // b = b / 3; b === 13
console.log(b)
b %= 5 // b = b % 5; b === 3
console.log(b)
b **= 2 // b = b ** 2; b === 9
console.log(b)