function convertToF(celsius) {
  let fahrenheit;
  return fahrenheit;
}

console.log(convertToF(30));

/*

convertToF(0) should return a number
convertToF(-30) should return a value of -22
convertToF(-10) should return a value of 14
convertToF(0) should return a value of 32
convertToF(20) should return a value of 68
convertToF(30) should return a value of 86

*/