Svetlanas hair is 4 centimeters long her hair grows 1.5 cm per month. Svetlana wants her hair to grow so that it's at least 7 cm long write an inequality to determine the number of months, m, it will take svetlana hair to grow so it's at least 7 cm long

1.5x + 4 (greater than or equal to) 7

It is greater than or equal to because she wants at least seven cm, which means that the length CAN be 7 cm, and it's greater than because at least means a minimum of, so 7 cm or longer.

You add four because that's how much hair she has already and you have 1.5x because that how much she growth per month. Plug in how many months for x and we'll get a length in that amount of time