To solve the inequality 5x + 2x < 4, we can start by simplifying the expression on the left-hand side. First, we combine like terms:
5x + 2x = 7x
So, the inequality now reads:
7x < 4
Next, we will solve for x by dividing both sides of the inequality by 7:
x < 4/7
This tells us that x can take any value less than 4/7.
To express this as a solution set, we can write it in interval notation:
(-∞, 4/7)
In conclusion, the solution set to the inequality 5x + 2x < 4 is all values of x that are less than 4/7, which in interval notation is (-∞, 4/7).